Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
2 | * linux/drivers/cpufreq/cpufreq.c | |
3 | * | |
4 | * Copyright (C) 2001 Russell King | |
5 | * (C) 2002 - 2003 Dominik Brodowski <linux@brodo.de> | |
bb176f7d | 6 | * (C) 2013 Viresh Kumar <viresh.kumar@linaro.org> |
1da177e4 | 7 | * |
c32b6b8e | 8 | * Oct 2005 - Ashok Raj <ashok.raj@intel.com> |
32ee8c3e | 9 | * Added handling for CPU hotplug |
8ff69732 DJ |
10 | * Feb 2006 - Jacob Shin <jacob.shin@amd.com> |
11 | * Fix handling for CPU hotplug -- affected CPUs | |
c32b6b8e | 12 | * |
1da177e4 LT |
13 | * This program is free software; you can redistribute it and/or modify |
14 | * it under the terms of the GNU General Public License version 2 as | |
15 | * published by the Free Software Foundation. | |
1da177e4 LT |
16 | */ |
17 | ||
db701151 VK |
18 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
19 | ||
5ff0a268 | 20 | #include <linux/cpu.h> |
1da177e4 LT |
21 | #include <linux/cpufreq.h> |
22 | #include <linux/delay.h> | |
1da177e4 | 23 | #include <linux/device.h> |
5ff0a268 VK |
24 | #include <linux/init.h> |
25 | #include <linux/kernel_stat.h> | |
26 | #include <linux/module.h> | |
3fc54d37 | 27 | #include <linux/mutex.h> |
5ff0a268 | 28 | #include <linux/slab.h> |
2f0aea93 | 29 | #include <linux/suspend.h> |
90de2a4a | 30 | #include <linux/syscore_ops.h> |
5ff0a268 | 31 | #include <linux/tick.h> |
6f4f2723 TR |
32 | #include <trace/events/power.h> |
33 | ||
b4f0676f | 34 | static LIST_HEAD(cpufreq_policy_list); |
f963735a VK |
35 | |
36 | static inline bool policy_is_inactive(struct cpufreq_policy *policy) | |
37 | { | |
38 | return cpumask_empty(policy->cpus); | |
39 | } | |
40 | ||
f963735a | 41 | /* Macros to iterate over CPU policies */ |
fd7dc7e6 EB |
42 | #define for_each_suitable_policy(__policy, __active) \ |
43 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) \ | |
44 | if ((__active) == !policy_is_inactive(__policy)) | |
f963735a VK |
45 | |
46 | #define for_each_active_policy(__policy) \ | |
47 | for_each_suitable_policy(__policy, true) | |
48 | #define for_each_inactive_policy(__policy) \ | |
49 | for_each_suitable_policy(__policy, false) | |
50 | ||
51 | #define for_each_policy(__policy) \ | |
b4f0676f VK |
52 | list_for_each_entry(__policy, &cpufreq_policy_list, policy_list) |
53 | ||
f7b27061 VK |
54 | /* Iterate over governors */ |
55 | static LIST_HEAD(cpufreq_governor_list); | |
56 | #define for_each_governor(__governor) \ | |
57 | list_for_each_entry(__governor, &cpufreq_governor_list, governor_list) | |
58 | ||
1da177e4 | 59 | /** |
cd878479 | 60 | * The "cpufreq driver" - the arch- or hardware-dependent low |
1da177e4 LT |
61 | * level driver of CPUFreq support, and its spinlock. This lock |
62 | * also protects the cpufreq_cpu_data array. | |
63 | */ | |
1c3d85dd | 64 | static struct cpufreq_driver *cpufreq_driver; |
7a6aedfa | 65 | static DEFINE_PER_CPU(struct cpufreq_policy *, cpufreq_cpu_data); |
bb176f7d | 66 | static DEFINE_RWLOCK(cpufreq_driver_lock); |
bb176f7d | 67 | |
2f0aea93 VK |
68 | /* Flag to suspend/resume CPUFreq governors */ |
69 | static bool cpufreq_suspended; | |
1da177e4 | 70 | |
9c0ebcf7 VK |
71 | static inline bool has_target(void) |
72 | { | |
73 | return cpufreq_driver->target_index || cpufreq_driver->target; | |
74 | } | |
75 | ||
1da177e4 | 76 | /* internal prototypes */ |
d92d50a4 | 77 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy); |
a92604b4 RW |
78 | static int cpufreq_init_governor(struct cpufreq_policy *policy); |
79 | static void cpufreq_exit_governor(struct cpufreq_policy *policy); | |
0a300767 | 80 | static int cpufreq_start_governor(struct cpufreq_policy *policy); |
a92604b4 RW |
81 | static void cpufreq_stop_governor(struct cpufreq_policy *policy); |
82 | static void cpufreq_governor_limits(struct cpufreq_policy *policy); | |
45482c70 | 83 | |
1da177e4 | 84 | /** |
32ee8c3e DJ |
85 | * Two notifier lists: the "policy" list is involved in the |
86 | * validation process for a new CPU frequency policy; the | |
1da177e4 LT |
87 | * "transition" list for kernel code that needs to handle |
88 | * changes to devices when the CPU clock speed changes. | |
89 | * The mutex locks both lists. | |
90 | */ | |
e041c683 | 91 | static BLOCKING_NOTIFIER_HEAD(cpufreq_policy_notifier_list); |
b4dfdbb3 | 92 | static struct srcu_notifier_head cpufreq_transition_notifier_list; |
1da177e4 | 93 | |
74212ca4 | 94 | static bool init_cpufreq_transition_notifier_list_called; |
b4dfdbb3 AS |
95 | static int __init init_cpufreq_transition_notifier_list(void) |
96 | { | |
97 | srcu_init_notifier_head(&cpufreq_transition_notifier_list); | |
74212ca4 | 98 | init_cpufreq_transition_notifier_list_called = true; |
b4dfdbb3 AS |
99 | return 0; |
100 | } | |
b3438f82 | 101 | pure_initcall(init_cpufreq_transition_notifier_list); |
1da177e4 | 102 | |
a7b422cd | 103 | static int off __read_mostly; |
da584455 | 104 | static int cpufreq_disabled(void) |
a7b422cd KRW |
105 | { |
106 | return off; | |
107 | } | |
108 | void disable_cpufreq(void) | |
109 | { | |
110 | off = 1; | |
111 | } | |
29464f28 | 112 | static DEFINE_MUTEX(cpufreq_governor_mutex); |
1da177e4 | 113 | |
4d5dcc42 VK |
114 | bool have_governor_per_policy(void) |
115 | { | |
0b981e70 | 116 | return !!(cpufreq_driver->flags & CPUFREQ_HAVE_GOVERNOR_PER_POLICY); |
4d5dcc42 | 117 | } |
3f869d6d | 118 | EXPORT_SYMBOL_GPL(have_governor_per_policy); |
4d5dcc42 | 119 | |
944e9a03 VK |
120 | struct kobject *get_governor_parent_kobj(struct cpufreq_policy *policy) |
121 | { | |
122 | if (have_governor_per_policy()) | |
123 | return &policy->kobj; | |
124 | else | |
125 | return cpufreq_global_kobject; | |
126 | } | |
127 | EXPORT_SYMBOL_GPL(get_governor_parent_kobj); | |
128 | ||
72a4ce34 VK |
129 | static inline u64 get_cpu_idle_time_jiffy(unsigned int cpu, u64 *wall) |
130 | { | |
131 | u64 idle_time; | |
132 | u64 cur_wall_time; | |
133 | u64 busy_time; | |
134 | ||
7fb1327e | 135 | cur_wall_time = jiffies64_to_nsecs(get_jiffies_64()); |
72a4ce34 VK |
136 | |
137 | busy_time = kcpustat_cpu(cpu).cpustat[CPUTIME_USER]; | |
138 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SYSTEM]; | |
139 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_IRQ]; | |
140 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_SOFTIRQ]; | |
141 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; | |
142 | busy_time += kcpustat_cpu(cpu).cpustat[CPUTIME_NICE]; | |
143 | ||
144 | idle_time = cur_wall_time - busy_time; | |
145 | if (wall) | |
7fb1327e | 146 | *wall = div_u64(cur_wall_time, NSEC_PER_USEC); |
72a4ce34 | 147 | |
7fb1327e | 148 | return div_u64(idle_time, NSEC_PER_USEC); |
72a4ce34 VK |
149 | } |
150 | ||
151 | u64 get_cpu_idle_time(unsigned int cpu, u64 *wall, int io_busy) | |
152 | { | |
153 | u64 idle_time = get_cpu_idle_time_us(cpu, io_busy ? wall : NULL); | |
154 | ||
155 | if (idle_time == -1ULL) | |
156 | return get_cpu_idle_time_jiffy(cpu, wall); | |
157 | else if (!io_busy) | |
158 | idle_time += get_cpu_iowait_time_us(cpu, wall); | |
159 | ||
160 | return idle_time; | |
161 | } | |
162 | EXPORT_SYMBOL_GPL(get_cpu_idle_time); | |
163 | ||
70e9e778 VK |
164 | /* |
165 | * This is a generic cpufreq init() routine which can be used by cpufreq | |
166 | * drivers of SMP systems. It will do following: | |
167 | * - validate & show freq table passed | |
168 | * - set policies transition latency | |
169 | * - policy->cpus with all possible CPUs | |
170 | */ | |
171 | int cpufreq_generic_init(struct cpufreq_policy *policy, | |
172 | struct cpufreq_frequency_table *table, | |
173 | unsigned int transition_latency) | |
174 | { | |
175 | int ret; | |
176 | ||
177 | ret = cpufreq_table_validate_and_show(policy, table); | |
178 | if (ret) { | |
179 | pr_err("%s: invalid frequency table: %d\n", __func__, ret); | |
180 | return ret; | |
181 | } | |
182 | ||
183 | policy->cpuinfo.transition_latency = transition_latency; | |
184 | ||
185 | /* | |
58405af6 | 186 | * The driver only supports the SMP configuration where all processors |
70e9e778 VK |
187 | * share the clock and voltage and clock. |
188 | */ | |
189 | cpumask_setall(policy->cpus); | |
190 | ||
191 | return 0; | |
192 | } | |
193 | EXPORT_SYMBOL_GPL(cpufreq_generic_init); | |
194 | ||
1f0bd44e | 195 | struct cpufreq_policy *cpufreq_cpu_get_raw(unsigned int cpu) |
652ed95d VK |
196 | { |
197 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); | |
198 | ||
988bed09 VK |
199 | return policy && cpumask_test_cpu(cpu, policy->cpus) ? policy : NULL; |
200 | } | |
1f0bd44e | 201 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get_raw); |
988bed09 VK |
202 | |
203 | unsigned int cpufreq_generic_get(unsigned int cpu) | |
204 | { | |
205 | struct cpufreq_policy *policy = cpufreq_cpu_get_raw(cpu); | |
206 | ||
652ed95d | 207 | if (!policy || IS_ERR(policy->clk)) { |
e837f9b5 JP |
208 | pr_err("%s: No %s associated to cpu: %d\n", |
209 | __func__, policy ? "clk" : "policy", cpu); | |
652ed95d VK |
210 | return 0; |
211 | } | |
212 | ||
213 | return clk_get_rate(policy->clk) / 1000; | |
214 | } | |
215 | EXPORT_SYMBOL_GPL(cpufreq_generic_get); | |
216 | ||
50e9c852 VK |
217 | /** |
218 | * cpufreq_cpu_get: returns policy for a cpu and marks it busy. | |
219 | * | |
220 | * @cpu: cpu to find policy for. | |
221 | * | |
222 | * This returns policy for 'cpu', returns NULL if it doesn't exist. | |
223 | * It also increments the kobject reference count to mark it busy and so would | |
224 | * require a corresponding call to cpufreq_cpu_put() to decrement it back. | |
225 | * If corresponding call cpufreq_cpu_put() isn't made, the policy wouldn't be | |
226 | * freed as that depends on the kobj count. | |
227 | * | |
50e9c852 VK |
228 | * Return: A valid policy on success, otherwise NULL on failure. |
229 | */ | |
6eed9404 | 230 | struct cpufreq_policy *cpufreq_cpu_get(unsigned int cpu) |
1da177e4 | 231 | { |
6eed9404 | 232 | struct cpufreq_policy *policy = NULL; |
1da177e4 LT |
233 | unsigned long flags; |
234 | ||
1b947c90 | 235 | if (WARN_ON(cpu >= nr_cpu_ids)) |
6eed9404 VK |
236 | return NULL; |
237 | ||
1da177e4 | 238 | /* get the cpufreq driver */ |
1c3d85dd | 239 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1da177e4 | 240 | |
6eed9404 VK |
241 | if (cpufreq_driver) { |
242 | /* get the CPU */ | |
988bed09 | 243 | policy = cpufreq_cpu_get_raw(cpu); |
6eed9404 VK |
244 | if (policy) |
245 | kobject_get(&policy->kobj); | |
246 | } | |
1da177e4 | 247 | |
6eed9404 | 248 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 249 | |
3a3e9e06 | 250 | return policy; |
a9144436 | 251 | } |
1da177e4 LT |
252 | EXPORT_SYMBOL_GPL(cpufreq_cpu_get); |
253 | ||
50e9c852 VK |
254 | /** |
255 | * cpufreq_cpu_put: Decrements the usage count of a policy | |
256 | * | |
257 | * @policy: policy earlier returned by cpufreq_cpu_get(). | |
258 | * | |
259 | * This decrements the kobject reference count incremented earlier by calling | |
260 | * cpufreq_cpu_get(). | |
50e9c852 | 261 | */ |
3a3e9e06 | 262 | void cpufreq_cpu_put(struct cpufreq_policy *policy) |
1da177e4 | 263 | { |
6eed9404 | 264 | kobject_put(&policy->kobj); |
1da177e4 LT |
265 | } |
266 | EXPORT_SYMBOL_GPL(cpufreq_cpu_put); | |
267 | ||
1da177e4 LT |
268 | /********************************************************************* |
269 | * EXTERNALLY AFFECTING FREQUENCY CHANGES * | |
270 | *********************************************************************/ | |
271 | ||
272 | /** | |
273 | * adjust_jiffies - adjust the system "loops_per_jiffy" | |
274 | * | |
275 | * This function alters the system "loops_per_jiffy" for the clock | |
276 | * speed change. Note that loops_per_jiffy cannot be updated on SMP | |
32ee8c3e | 277 | * systems as each CPU might be scaled differently. So, use the arch |
1da177e4 LT |
278 | * per-CPU loops_per_jiffy value wherever possible. |
279 | */ | |
858119e1 | 280 | static void adjust_jiffies(unsigned long val, struct cpufreq_freqs *ci) |
1da177e4 | 281 | { |
39c132ee VK |
282 | #ifndef CONFIG_SMP |
283 | static unsigned long l_p_j_ref; | |
284 | static unsigned int l_p_j_ref_freq; | |
285 | ||
1da177e4 LT |
286 | if (ci->flags & CPUFREQ_CONST_LOOPS) |
287 | return; | |
288 | ||
289 | if (!l_p_j_ref_freq) { | |
290 | l_p_j_ref = loops_per_jiffy; | |
291 | l_p_j_ref_freq = ci->old; | |
e837f9b5 JP |
292 | pr_debug("saving %lu as reference value for loops_per_jiffy; freq is %u kHz\n", |
293 | l_p_j_ref, l_p_j_ref_freq); | |
1da177e4 | 294 | } |
0b443ead | 295 | if (val == CPUFREQ_POSTCHANGE && ci->old != ci->new) { |
e08f5f5b GS |
296 | loops_per_jiffy = cpufreq_scale(l_p_j_ref, l_p_j_ref_freq, |
297 | ci->new); | |
e837f9b5 JP |
298 | pr_debug("scaling loops_per_jiffy to %lu for frequency %u kHz\n", |
299 | loops_per_jiffy, ci->new); | |
1da177e4 | 300 | } |
1da177e4 | 301 | #endif |
39c132ee | 302 | } |
1da177e4 | 303 | |
0956df9c | 304 | static void __cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb | 305 | struct cpufreq_freqs *freqs, unsigned int state) |
1da177e4 LT |
306 | { |
307 | BUG_ON(irqs_disabled()); | |
308 | ||
d5aaffa9 DB |
309 | if (cpufreq_disabled()) |
310 | return; | |
311 | ||
1c3d85dd | 312 | freqs->flags = cpufreq_driver->flags; |
2d06d8c4 | 313 | pr_debug("notification %u of frequency transition to %u kHz\n", |
e837f9b5 | 314 | state, freqs->new); |
1da177e4 | 315 | |
1da177e4 | 316 | switch (state) { |
e4472cb3 | 317 | |
1da177e4 | 318 | case CPUFREQ_PRECHANGE: |
32ee8c3e | 319 | /* detect if the driver reported a value as "old frequency" |
e4472cb3 DJ |
320 | * which is not equal to what the cpufreq core thinks is |
321 | * "old frequency". | |
1da177e4 | 322 | */ |
1c3d85dd | 323 | if (!(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e4472cb3 DJ |
324 | if ((policy) && (policy->cpu == freqs->cpu) && |
325 | (policy->cur) && (policy->cur != freqs->old)) { | |
e837f9b5 JP |
326 | pr_debug("Warning: CPU frequency is %u, cpufreq assumed %u kHz\n", |
327 | freqs->old, policy->cur); | |
e4472cb3 | 328 | freqs->old = policy->cur; |
1da177e4 LT |
329 | } |
330 | } | |
b4dfdbb3 | 331 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 332 | CPUFREQ_PRECHANGE, freqs); |
1da177e4 LT |
333 | adjust_jiffies(CPUFREQ_PRECHANGE, freqs); |
334 | break; | |
e4472cb3 | 335 | |
1da177e4 LT |
336 | case CPUFREQ_POSTCHANGE: |
337 | adjust_jiffies(CPUFREQ_POSTCHANGE, freqs); | |
e837f9b5 JP |
338 | pr_debug("FREQ: %lu - CPU: %lu\n", |
339 | (unsigned long)freqs->new, (unsigned long)freqs->cpu); | |
25e41933 | 340 | trace_cpu_frequency(freqs->new, freqs->cpu); |
1aefc75b | 341 | cpufreq_stats_record_transition(policy, freqs->new); |
b4dfdbb3 | 342 | srcu_notifier_call_chain(&cpufreq_transition_notifier_list, |
e041c683 | 343 | CPUFREQ_POSTCHANGE, freqs); |
e4472cb3 DJ |
344 | if (likely(policy) && likely(policy->cpu == freqs->cpu)) |
345 | policy->cur = freqs->new; | |
1da177e4 LT |
346 | break; |
347 | } | |
1da177e4 | 348 | } |
bb176f7d | 349 | |
b43a7ffb VK |
350 | /** |
351 | * cpufreq_notify_transition - call notifier chain and adjust_jiffies | |
352 | * on frequency transition. | |
353 | * | |
354 | * This function calls the transition notifiers and the "adjust_jiffies" | |
355 | * function. It is called twice on all CPU frequency changes that have | |
356 | * external effects. | |
357 | */ | |
236a9800 | 358 | static void cpufreq_notify_transition(struct cpufreq_policy *policy, |
b43a7ffb VK |
359 | struct cpufreq_freqs *freqs, unsigned int state) |
360 | { | |
361 | for_each_cpu(freqs->cpu, policy->cpus) | |
362 | __cpufreq_notify_transition(policy, freqs, state); | |
363 | } | |
1da177e4 | 364 | |
f7ba3b41 | 365 | /* Do post notifications when there are chances that transition has failed */ |
236a9800 | 366 | static void cpufreq_notify_post_transition(struct cpufreq_policy *policy, |
f7ba3b41 VK |
367 | struct cpufreq_freqs *freqs, int transition_failed) |
368 | { | |
369 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
370 | if (!transition_failed) | |
371 | return; | |
372 | ||
373 | swap(freqs->old, freqs->new); | |
374 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
375 | cpufreq_notify_transition(policy, freqs, CPUFREQ_POSTCHANGE); | |
376 | } | |
f7ba3b41 | 377 | |
12478cf0 SB |
378 | void cpufreq_freq_transition_begin(struct cpufreq_policy *policy, |
379 | struct cpufreq_freqs *freqs) | |
380 | { | |
ca654dc3 SB |
381 | |
382 | /* | |
383 | * Catch double invocations of _begin() which lead to self-deadlock. | |
384 | * ASYNC_NOTIFICATION drivers are left out because the cpufreq core | |
385 | * doesn't invoke _begin() on their behalf, and hence the chances of | |
386 | * double invocations are very low. Moreover, there are scenarios | |
387 | * where these checks can emit false-positive warnings in these | |
388 | * drivers; so we avoid that by skipping them altogether. | |
389 | */ | |
390 | WARN_ON(!(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION) | |
391 | && current == policy->transition_task); | |
392 | ||
12478cf0 SB |
393 | wait: |
394 | wait_event(policy->transition_wait, !policy->transition_ongoing); | |
395 | ||
396 | spin_lock(&policy->transition_lock); | |
397 | ||
398 | if (unlikely(policy->transition_ongoing)) { | |
399 | spin_unlock(&policy->transition_lock); | |
400 | goto wait; | |
401 | } | |
402 | ||
403 | policy->transition_ongoing = true; | |
ca654dc3 | 404 | policy->transition_task = current; |
12478cf0 SB |
405 | |
406 | spin_unlock(&policy->transition_lock); | |
407 | ||
408 | cpufreq_notify_transition(policy, freqs, CPUFREQ_PRECHANGE); | |
409 | } | |
410 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_begin); | |
411 | ||
412 | void cpufreq_freq_transition_end(struct cpufreq_policy *policy, | |
413 | struct cpufreq_freqs *freqs, int transition_failed) | |
414 | { | |
415 | if (unlikely(WARN_ON(!policy->transition_ongoing))) | |
416 | return; | |
417 | ||
418 | cpufreq_notify_post_transition(policy, freqs, transition_failed); | |
419 | ||
420 | policy->transition_ongoing = false; | |
ca654dc3 | 421 | policy->transition_task = NULL; |
12478cf0 SB |
422 | |
423 | wake_up(&policy->transition_wait); | |
424 | } | |
425 | EXPORT_SYMBOL_GPL(cpufreq_freq_transition_end); | |
426 | ||
b7898fda RW |
427 | /* |
428 | * Fast frequency switching status count. Positive means "enabled", negative | |
429 | * means "disabled" and 0 means "not decided yet". | |
430 | */ | |
431 | static int cpufreq_fast_switch_count; | |
432 | static DEFINE_MUTEX(cpufreq_fast_switch_lock); | |
433 | ||
434 | static void cpufreq_list_transition_notifiers(void) | |
435 | { | |
436 | struct notifier_block *nb; | |
437 | ||
438 | pr_info("Registered transition notifiers:\n"); | |
439 | ||
440 | mutex_lock(&cpufreq_transition_notifier_list.mutex); | |
441 | ||
442 | for (nb = cpufreq_transition_notifier_list.head; nb; nb = nb->next) | |
443 | pr_info("%pF\n", nb->notifier_call); | |
444 | ||
445 | mutex_unlock(&cpufreq_transition_notifier_list.mutex); | |
446 | } | |
447 | ||
448 | /** | |
449 | * cpufreq_enable_fast_switch - Enable fast frequency switching for policy. | |
450 | * @policy: cpufreq policy to enable fast frequency switching for. | |
451 | * | |
452 | * Try to enable fast frequency switching for @policy. | |
453 | * | |
454 | * The attempt will fail if there is at least one transition notifier registered | |
455 | * at this point, as fast frequency switching is quite fundamentally at odds | |
456 | * with transition notifiers. Thus if successful, it will make registration of | |
457 | * transition notifiers fail going forward. | |
458 | */ | |
459 | void cpufreq_enable_fast_switch(struct cpufreq_policy *policy) | |
460 | { | |
461 | lockdep_assert_held(&policy->rwsem); | |
462 | ||
463 | if (!policy->fast_switch_possible) | |
464 | return; | |
465 | ||
466 | mutex_lock(&cpufreq_fast_switch_lock); | |
467 | if (cpufreq_fast_switch_count >= 0) { | |
468 | cpufreq_fast_switch_count++; | |
469 | policy->fast_switch_enabled = true; | |
470 | } else { | |
471 | pr_warn("CPU%u: Fast frequency switching not enabled\n", | |
472 | policy->cpu); | |
473 | cpufreq_list_transition_notifiers(); | |
474 | } | |
475 | mutex_unlock(&cpufreq_fast_switch_lock); | |
476 | } | |
477 | EXPORT_SYMBOL_GPL(cpufreq_enable_fast_switch); | |
478 | ||
6c9d9c81 RW |
479 | /** |
480 | * cpufreq_disable_fast_switch - Disable fast frequency switching for policy. | |
481 | * @policy: cpufreq policy to disable fast frequency switching for. | |
482 | */ | |
483 | void cpufreq_disable_fast_switch(struct cpufreq_policy *policy) | |
b7898fda RW |
484 | { |
485 | mutex_lock(&cpufreq_fast_switch_lock); | |
486 | if (policy->fast_switch_enabled) { | |
487 | policy->fast_switch_enabled = false; | |
488 | if (!WARN_ON(cpufreq_fast_switch_count <= 0)) | |
489 | cpufreq_fast_switch_count--; | |
490 | } | |
491 | mutex_unlock(&cpufreq_fast_switch_lock); | |
492 | } | |
6c9d9c81 | 493 | EXPORT_SYMBOL_GPL(cpufreq_disable_fast_switch); |
1da177e4 | 494 | |
e3c06236 SM |
495 | /** |
496 | * cpufreq_driver_resolve_freq - Map a target frequency to a driver-supported | |
497 | * one. | |
498 | * @target_freq: target frequency to resolve. | |
499 | * | |
500 | * The target to driver frequency mapping is cached in the policy. | |
501 | * | |
502 | * Return: Lowest driver-supported frequency greater than or equal to the | |
503 | * given target_freq, subject to policy (min/max) and driver limitations. | |
504 | */ | |
505 | unsigned int cpufreq_driver_resolve_freq(struct cpufreq_policy *policy, | |
506 | unsigned int target_freq) | |
507 | { | |
508 | target_freq = clamp_val(target_freq, policy->min, policy->max); | |
509 | policy->cached_target_freq = target_freq; | |
abe8bd02 VK |
510 | |
511 | if (cpufreq_driver->target_index) { | |
512 | int idx; | |
513 | ||
514 | idx = cpufreq_frequency_table_target(policy, target_freq, | |
515 | CPUFREQ_RELATION_L); | |
516 | policy->cached_resolved_idx = idx; | |
517 | return policy->freq_table[idx].frequency; | |
518 | } | |
519 | ||
e3c06236 SM |
520 | if (cpufreq_driver->resolve_freq) |
521 | return cpufreq_driver->resolve_freq(policy, target_freq); | |
abe8bd02 VK |
522 | |
523 | return target_freq; | |
e3c06236 | 524 | } |
ae2c1ca6 | 525 | EXPORT_SYMBOL_GPL(cpufreq_driver_resolve_freq); |
e3c06236 | 526 | |
1da177e4 LT |
527 | /********************************************************************* |
528 | * SYSFS INTERFACE * | |
529 | *********************************************************************/ | |
8a5c74a1 | 530 | static ssize_t show_boost(struct kobject *kobj, |
6f19efc0 LM |
531 | struct attribute *attr, char *buf) |
532 | { | |
533 | return sprintf(buf, "%d\n", cpufreq_driver->boost_enabled); | |
534 | } | |
535 | ||
536 | static ssize_t store_boost(struct kobject *kobj, struct attribute *attr, | |
537 | const char *buf, size_t count) | |
538 | { | |
539 | int ret, enable; | |
540 | ||
541 | ret = sscanf(buf, "%d", &enable); | |
542 | if (ret != 1 || enable < 0 || enable > 1) | |
543 | return -EINVAL; | |
544 | ||
545 | if (cpufreq_boost_trigger_state(enable)) { | |
e837f9b5 JP |
546 | pr_err("%s: Cannot %s BOOST!\n", |
547 | __func__, enable ? "enable" : "disable"); | |
6f19efc0 LM |
548 | return -EINVAL; |
549 | } | |
550 | ||
e837f9b5 JP |
551 | pr_debug("%s: cpufreq BOOST %s\n", |
552 | __func__, enable ? "enabled" : "disabled"); | |
6f19efc0 LM |
553 | |
554 | return count; | |
555 | } | |
556 | define_one_global_rw(boost); | |
1da177e4 | 557 | |
42f91fa1 | 558 | static struct cpufreq_governor *find_governor(const char *str_governor) |
3bcb09a3 JF |
559 | { |
560 | struct cpufreq_governor *t; | |
561 | ||
f7b27061 | 562 | for_each_governor(t) |
7c4f4539 | 563 | if (!strncasecmp(str_governor, t->name, CPUFREQ_NAME_LEN)) |
3bcb09a3 JF |
564 | return t; |
565 | ||
566 | return NULL; | |
567 | } | |
568 | ||
1da177e4 LT |
569 | /** |
570 | * cpufreq_parse_governor - parse a governor string | |
571 | */ | |
905d77cd | 572 | static int cpufreq_parse_governor(char *str_governor, unsigned int *policy, |
1da177e4 LT |
573 | struct cpufreq_governor **governor) |
574 | { | |
3bcb09a3 | 575 | int err = -EINVAL; |
1c3d85dd | 576 | |
1c3d85dd | 577 | if (cpufreq_driver->setpolicy) { |
7c4f4539 | 578 | if (!strncasecmp(str_governor, "performance", CPUFREQ_NAME_LEN)) { |
1da177e4 | 579 | *policy = CPUFREQ_POLICY_PERFORMANCE; |
3bcb09a3 | 580 | err = 0; |
7c4f4539 | 581 | } else if (!strncasecmp(str_governor, "powersave", |
e08f5f5b | 582 | CPUFREQ_NAME_LEN)) { |
1da177e4 | 583 | *policy = CPUFREQ_POLICY_POWERSAVE; |
3bcb09a3 | 584 | err = 0; |
1da177e4 | 585 | } |
2e1cc3a5 | 586 | } else { |
1da177e4 | 587 | struct cpufreq_governor *t; |
3bcb09a3 | 588 | |
3fc54d37 | 589 | mutex_lock(&cpufreq_governor_mutex); |
3bcb09a3 | 590 | |
42f91fa1 | 591 | t = find_governor(str_governor); |
3bcb09a3 | 592 | |
ea714970 | 593 | if (t == NULL) { |
1a8e1463 | 594 | int ret; |
ea714970 | 595 | |
1a8e1463 KC |
596 | mutex_unlock(&cpufreq_governor_mutex); |
597 | ret = request_module("cpufreq_%s", str_governor); | |
598 | mutex_lock(&cpufreq_governor_mutex); | |
ea714970 | 599 | |
1a8e1463 | 600 | if (ret == 0) |
42f91fa1 | 601 | t = find_governor(str_governor); |
ea714970 JF |
602 | } |
603 | ||
3bcb09a3 JF |
604 | if (t != NULL) { |
605 | *governor = t; | |
606 | err = 0; | |
1da177e4 | 607 | } |
3bcb09a3 | 608 | |
3fc54d37 | 609 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 | 610 | } |
3bcb09a3 | 611 | return err; |
1da177e4 | 612 | } |
1da177e4 | 613 | |
1da177e4 | 614 | /** |
e08f5f5b GS |
615 | * cpufreq_per_cpu_attr_read() / show_##file_name() - |
616 | * print out cpufreq information | |
1da177e4 LT |
617 | * |
618 | * Write out information from cpufreq_driver->policy[cpu]; object must be | |
619 | * "unsigned int". | |
620 | */ | |
621 | ||
32ee8c3e DJ |
622 | #define show_one(file_name, object) \ |
623 | static ssize_t show_##file_name \ | |
905d77cd | 624 | (struct cpufreq_policy *policy, char *buf) \ |
32ee8c3e | 625 | { \ |
29464f28 | 626 | return sprintf(buf, "%u\n", policy->object); \ |
1da177e4 LT |
627 | } |
628 | ||
629 | show_one(cpuinfo_min_freq, cpuinfo.min_freq); | |
630 | show_one(cpuinfo_max_freq, cpuinfo.max_freq); | |
ed129784 | 631 | show_one(cpuinfo_transition_latency, cpuinfo.transition_latency); |
1da177e4 LT |
632 | show_one(scaling_min_freq, min); |
633 | show_one(scaling_max_freq, max); | |
c034b02e | 634 | |
f8475cef LB |
635 | __weak unsigned int arch_freq_get_on_cpu(int cpu) |
636 | { | |
637 | return 0; | |
638 | } | |
639 | ||
09347b29 | 640 | static ssize_t show_scaling_cur_freq(struct cpufreq_policy *policy, char *buf) |
c034b02e DB |
641 | { |
642 | ssize_t ret; | |
f8475cef | 643 | unsigned int freq; |
c034b02e | 644 | |
f8475cef LB |
645 | freq = arch_freq_get_on_cpu(policy->cpu); |
646 | if (freq) | |
647 | ret = sprintf(buf, "%u\n", freq); | |
648 | else if (cpufreq_driver && cpufreq_driver->setpolicy && | |
649 | cpufreq_driver->get) | |
c034b02e DB |
650 | ret = sprintf(buf, "%u\n", cpufreq_driver->get(policy->cpu)); |
651 | else | |
652 | ret = sprintf(buf, "%u\n", policy->cur); | |
653 | return ret; | |
654 | } | |
1da177e4 | 655 | |
037ce839 | 656 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 657 | struct cpufreq_policy *new_policy); |
7970e08b | 658 | |
1da177e4 LT |
659 | /** |
660 | * cpufreq_per_cpu_attr_write() / store_##file_name() - sysfs write access | |
661 | */ | |
662 | #define store_one(file_name, object) \ | |
663 | static ssize_t store_##file_name \ | |
905d77cd | 664 | (struct cpufreq_policy *policy, const char *buf, size_t count) \ |
1da177e4 | 665 | { \ |
619c144c | 666 | int ret, temp; \ |
1da177e4 LT |
667 | struct cpufreq_policy new_policy; \ |
668 | \ | |
8fa5b631 | 669 | memcpy(&new_policy, policy, sizeof(*policy)); \ |
1da177e4 | 670 | \ |
29464f28 | 671 | ret = sscanf(buf, "%u", &new_policy.object); \ |
1da177e4 LT |
672 | if (ret != 1) \ |
673 | return -EINVAL; \ | |
674 | \ | |
619c144c | 675 | temp = new_policy.object; \ |
037ce839 | 676 | ret = cpufreq_set_policy(policy, &new_policy); \ |
619c144c VH |
677 | if (!ret) \ |
678 | policy->user_policy.object = temp; \ | |
1da177e4 LT |
679 | \ |
680 | return ret ? ret : count; \ | |
681 | } | |
682 | ||
29464f28 DJ |
683 | store_one(scaling_min_freq, min); |
684 | store_one(scaling_max_freq, max); | |
1da177e4 LT |
685 | |
686 | /** | |
687 | * show_cpuinfo_cur_freq - current CPU frequency as detected by hardware | |
688 | */ | |
905d77cd DJ |
689 | static ssize_t show_cpuinfo_cur_freq(struct cpufreq_policy *policy, |
690 | char *buf) | |
1da177e4 | 691 | { |
d92d50a4 | 692 | unsigned int cur_freq = __cpufreq_get(policy); |
9b4f603e RW |
693 | |
694 | if (cur_freq) | |
695 | return sprintf(buf, "%u\n", cur_freq); | |
696 | ||
697 | return sprintf(buf, "<unknown>\n"); | |
1da177e4 LT |
698 | } |
699 | ||
1da177e4 LT |
700 | /** |
701 | * show_scaling_governor - show the current policy for the specified CPU | |
702 | */ | |
905d77cd | 703 | static ssize_t show_scaling_governor(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 704 | { |
29464f28 | 705 | if (policy->policy == CPUFREQ_POLICY_POWERSAVE) |
1da177e4 LT |
706 | return sprintf(buf, "powersave\n"); |
707 | else if (policy->policy == CPUFREQ_POLICY_PERFORMANCE) | |
708 | return sprintf(buf, "performance\n"); | |
709 | else if (policy->governor) | |
4b972f0b | 710 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", |
29464f28 | 711 | policy->governor->name); |
1da177e4 LT |
712 | return -EINVAL; |
713 | } | |
714 | ||
1da177e4 LT |
715 | /** |
716 | * store_scaling_governor - store policy for the specified CPU | |
717 | */ | |
905d77cd DJ |
718 | static ssize_t store_scaling_governor(struct cpufreq_policy *policy, |
719 | const char *buf, size_t count) | |
1da177e4 | 720 | { |
5136fa56 | 721 | int ret; |
1da177e4 LT |
722 | char str_governor[16]; |
723 | struct cpufreq_policy new_policy; | |
724 | ||
8fa5b631 | 725 | memcpy(&new_policy, policy, sizeof(*policy)); |
1da177e4 | 726 | |
29464f28 | 727 | ret = sscanf(buf, "%15s", str_governor); |
1da177e4 LT |
728 | if (ret != 1) |
729 | return -EINVAL; | |
730 | ||
e08f5f5b GS |
731 | if (cpufreq_parse_governor(str_governor, &new_policy.policy, |
732 | &new_policy.governor)) | |
1da177e4 LT |
733 | return -EINVAL; |
734 | ||
037ce839 | 735 | ret = cpufreq_set_policy(policy, &new_policy); |
88dc4384 | 736 | return ret ? ret : count; |
1da177e4 LT |
737 | } |
738 | ||
739 | /** | |
740 | * show_scaling_driver - show the cpufreq driver currently loaded | |
741 | */ | |
905d77cd | 742 | static ssize_t show_scaling_driver(struct cpufreq_policy *policy, char *buf) |
1da177e4 | 743 | { |
1c3d85dd | 744 | return scnprintf(buf, CPUFREQ_NAME_PLEN, "%s\n", cpufreq_driver->name); |
1da177e4 LT |
745 | } |
746 | ||
747 | /** | |
748 | * show_scaling_available_governors - show the available CPUfreq governors | |
749 | */ | |
905d77cd DJ |
750 | static ssize_t show_scaling_available_governors(struct cpufreq_policy *policy, |
751 | char *buf) | |
1da177e4 LT |
752 | { |
753 | ssize_t i = 0; | |
754 | struct cpufreq_governor *t; | |
755 | ||
9c0ebcf7 | 756 | if (!has_target()) { |
1da177e4 LT |
757 | i += sprintf(buf, "performance powersave"); |
758 | goto out; | |
759 | } | |
760 | ||
f7b27061 | 761 | for_each_governor(t) { |
29464f28 DJ |
762 | if (i >= (ssize_t) ((PAGE_SIZE / sizeof(char)) |
763 | - (CPUFREQ_NAME_LEN + 2))) | |
1da177e4 | 764 | goto out; |
4b972f0b | 765 | i += scnprintf(&buf[i], CPUFREQ_NAME_PLEN, "%s ", t->name); |
1da177e4 | 766 | } |
7d5e350f | 767 | out: |
1da177e4 LT |
768 | i += sprintf(&buf[i], "\n"); |
769 | return i; | |
770 | } | |
e8628dd0 | 771 | |
f4fd3797 | 772 | ssize_t cpufreq_show_cpus(const struct cpumask *mask, char *buf) |
1da177e4 LT |
773 | { |
774 | ssize_t i = 0; | |
775 | unsigned int cpu; | |
776 | ||
835481d9 | 777 | for_each_cpu(cpu, mask) { |
1da177e4 LT |
778 | if (i) |
779 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), " "); | |
780 | i += scnprintf(&buf[i], (PAGE_SIZE - i - 2), "%u", cpu); | |
781 | if (i >= (PAGE_SIZE - 5)) | |
29464f28 | 782 | break; |
1da177e4 LT |
783 | } |
784 | i += sprintf(&buf[i], "\n"); | |
785 | return i; | |
786 | } | |
f4fd3797 | 787 | EXPORT_SYMBOL_GPL(cpufreq_show_cpus); |
1da177e4 | 788 | |
e8628dd0 DW |
789 | /** |
790 | * show_related_cpus - show the CPUs affected by each transition even if | |
791 | * hw coordination is in use | |
792 | */ | |
793 | static ssize_t show_related_cpus(struct cpufreq_policy *policy, char *buf) | |
794 | { | |
f4fd3797 | 795 | return cpufreq_show_cpus(policy->related_cpus, buf); |
e8628dd0 DW |
796 | } |
797 | ||
798 | /** | |
799 | * show_affected_cpus - show the CPUs affected by each transition | |
800 | */ | |
801 | static ssize_t show_affected_cpus(struct cpufreq_policy *policy, char *buf) | |
802 | { | |
f4fd3797 | 803 | return cpufreq_show_cpus(policy->cpus, buf); |
e8628dd0 DW |
804 | } |
805 | ||
9e76988e | 806 | static ssize_t store_scaling_setspeed(struct cpufreq_policy *policy, |
905d77cd | 807 | const char *buf, size_t count) |
9e76988e VP |
808 | { |
809 | unsigned int freq = 0; | |
810 | unsigned int ret; | |
811 | ||
879000f9 | 812 | if (!policy->governor || !policy->governor->store_setspeed) |
9e76988e VP |
813 | return -EINVAL; |
814 | ||
815 | ret = sscanf(buf, "%u", &freq); | |
816 | if (ret != 1) | |
817 | return -EINVAL; | |
818 | ||
819 | policy->governor->store_setspeed(policy, freq); | |
820 | ||
821 | return count; | |
822 | } | |
823 | ||
824 | static ssize_t show_scaling_setspeed(struct cpufreq_policy *policy, char *buf) | |
825 | { | |
879000f9 | 826 | if (!policy->governor || !policy->governor->show_setspeed) |
9e76988e VP |
827 | return sprintf(buf, "<unsupported>\n"); |
828 | ||
829 | return policy->governor->show_setspeed(policy, buf); | |
830 | } | |
1da177e4 | 831 | |
e2f74f35 | 832 | /** |
8bf1ac72 | 833 | * show_bios_limit - show the current cpufreq HW/BIOS limitation |
e2f74f35 TR |
834 | */ |
835 | static ssize_t show_bios_limit(struct cpufreq_policy *policy, char *buf) | |
836 | { | |
837 | unsigned int limit; | |
838 | int ret; | |
1c3d85dd RW |
839 | if (cpufreq_driver->bios_limit) { |
840 | ret = cpufreq_driver->bios_limit(policy->cpu, &limit); | |
e2f74f35 TR |
841 | if (!ret) |
842 | return sprintf(buf, "%u\n", limit); | |
843 | } | |
844 | return sprintf(buf, "%u\n", policy->cpuinfo.max_freq); | |
845 | } | |
846 | ||
6dad2a29 BP |
847 | cpufreq_freq_attr_ro_perm(cpuinfo_cur_freq, 0400); |
848 | cpufreq_freq_attr_ro(cpuinfo_min_freq); | |
849 | cpufreq_freq_attr_ro(cpuinfo_max_freq); | |
850 | cpufreq_freq_attr_ro(cpuinfo_transition_latency); | |
851 | cpufreq_freq_attr_ro(scaling_available_governors); | |
852 | cpufreq_freq_attr_ro(scaling_driver); | |
853 | cpufreq_freq_attr_ro(scaling_cur_freq); | |
854 | cpufreq_freq_attr_ro(bios_limit); | |
855 | cpufreq_freq_attr_ro(related_cpus); | |
856 | cpufreq_freq_attr_ro(affected_cpus); | |
857 | cpufreq_freq_attr_rw(scaling_min_freq); | |
858 | cpufreq_freq_attr_rw(scaling_max_freq); | |
859 | cpufreq_freq_attr_rw(scaling_governor); | |
860 | cpufreq_freq_attr_rw(scaling_setspeed); | |
1da177e4 | 861 | |
905d77cd | 862 | static struct attribute *default_attrs[] = { |
1da177e4 LT |
863 | &cpuinfo_min_freq.attr, |
864 | &cpuinfo_max_freq.attr, | |
ed129784 | 865 | &cpuinfo_transition_latency.attr, |
1da177e4 LT |
866 | &scaling_min_freq.attr, |
867 | &scaling_max_freq.attr, | |
868 | &affected_cpus.attr, | |
e8628dd0 | 869 | &related_cpus.attr, |
1da177e4 LT |
870 | &scaling_governor.attr, |
871 | &scaling_driver.attr, | |
872 | &scaling_available_governors.attr, | |
9e76988e | 873 | &scaling_setspeed.attr, |
1da177e4 LT |
874 | NULL |
875 | }; | |
876 | ||
29464f28 DJ |
877 | #define to_policy(k) container_of(k, struct cpufreq_policy, kobj) |
878 | #define to_attr(a) container_of(a, struct freq_attr, attr) | |
1da177e4 | 879 | |
29464f28 | 880 | static ssize_t show(struct kobject *kobj, struct attribute *attr, char *buf) |
1da177e4 | 881 | { |
905d77cd DJ |
882 | struct cpufreq_policy *policy = to_policy(kobj); |
883 | struct freq_attr *fattr = to_attr(attr); | |
1b750e3b | 884 | ssize_t ret; |
6eed9404 | 885 | |
ad7722da | 886 | down_read(&policy->rwsem); |
6541aef0 | 887 | ret = fattr->show(policy, buf); |
ad7722da | 888 | up_read(&policy->rwsem); |
1b750e3b | 889 | |
1da177e4 LT |
890 | return ret; |
891 | } | |
892 | ||
905d77cd DJ |
893 | static ssize_t store(struct kobject *kobj, struct attribute *attr, |
894 | const char *buf, size_t count) | |
1da177e4 | 895 | { |
905d77cd DJ |
896 | struct cpufreq_policy *policy = to_policy(kobj); |
897 | struct freq_attr *fattr = to_attr(attr); | |
a07530b4 | 898 | ssize_t ret = -EINVAL; |
6eed9404 | 899 | |
a92551e4 | 900 | cpus_read_lock(); |
4f750c93 | 901 | |
6541aef0 RW |
902 | if (cpu_online(policy->cpu)) { |
903 | down_write(&policy->rwsem); | |
e08f5f5b | 904 | ret = fattr->store(policy, buf, count); |
6541aef0 RW |
905 | up_write(&policy->rwsem); |
906 | } | |
e08f5f5b | 907 | |
a92551e4 | 908 | cpus_read_unlock(); |
4f750c93 | 909 | |
1da177e4 LT |
910 | return ret; |
911 | } | |
912 | ||
905d77cd | 913 | static void cpufreq_sysfs_release(struct kobject *kobj) |
1da177e4 | 914 | { |
905d77cd | 915 | struct cpufreq_policy *policy = to_policy(kobj); |
2d06d8c4 | 916 | pr_debug("last reference is dropped\n"); |
1da177e4 LT |
917 | complete(&policy->kobj_unregister); |
918 | } | |
919 | ||
52cf25d0 | 920 | static const struct sysfs_ops sysfs_ops = { |
1da177e4 LT |
921 | .show = show, |
922 | .store = store, | |
923 | }; | |
924 | ||
925 | static struct kobj_type ktype_cpufreq = { | |
926 | .sysfs_ops = &sysfs_ops, | |
927 | .default_attrs = default_attrs, | |
928 | .release = cpufreq_sysfs_release, | |
929 | }; | |
930 | ||
2f0ba790 | 931 | static void add_cpu_dev_symlink(struct cpufreq_policy *policy, unsigned int cpu) |
87549141 | 932 | { |
2f0ba790 RW |
933 | struct device *dev = get_cpu_device(cpu); |
934 | ||
935 | if (!dev) | |
936 | return; | |
937 | ||
938 | if (cpumask_test_and_set_cpu(cpu, policy->real_cpus)) | |
939 | return; | |
940 | ||
26619804 | 941 | dev_dbg(dev, "%s: Adding symlink\n", __func__); |
2f0ba790 RW |
942 | if (sysfs_create_link(&dev->kobj, &policy->kobj, "cpufreq")) |
943 | dev_err(dev, "cpufreq symlink creation failed\n"); | |
87549141 VK |
944 | } |
945 | ||
26619804 VK |
946 | static void remove_cpu_dev_symlink(struct cpufreq_policy *policy, |
947 | struct device *dev) | |
87549141 | 948 | { |
26619804 VK |
949 | dev_dbg(dev, "%s: Removing symlink\n", __func__); |
950 | sysfs_remove_link(&dev->kobj, "cpufreq"); | |
87549141 VK |
951 | } |
952 | ||
d9612a49 | 953 | static int cpufreq_add_dev_interface(struct cpufreq_policy *policy) |
909a694e DJ |
954 | { |
955 | struct freq_attr **drv_attr; | |
909a694e | 956 | int ret = 0; |
909a694e | 957 | |
909a694e | 958 | /* set up files for this cpu device */ |
1c3d85dd | 959 | drv_attr = cpufreq_driver->attr; |
f13f1184 | 960 | while (drv_attr && *drv_attr) { |
909a694e DJ |
961 | ret = sysfs_create_file(&policy->kobj, &((*drv_attr)->attr)); |
962 | if (ret) | |
6d4e81ed | 963 | return ret; |
909a694e DJ |
964 | drv_attr++; |
965 | } | |
1c3d85dd | 966 | if (cpufreq_driver->get) { |
909a694e DJ |
967 | ret = sysfs_create_file(&policy->kobj, &cpuinfo_cur_freq.attr); |
968 | if (ret) | |
6d4e81ed | 969 | return ret; |
909a694e | 970 | } |
c034b02e DB |
971 | |
972 | ret = sysfs_create_file(&policy->kobj, &scaling_cur_freq.attr); | |
973 | if (ret) | |
6d4e81ed | 974 | return ret; |
c034b02e | 975 | |
1c3d85dd | 976 | if (cpufreq_driver->bios_limit) { |
e2f74f35 TR |
977 | ret = sysfs_create_file(&policy->kobj, &bios_limit.attr); |
978 | if (ret) | |
6d4e81ed | 979 | return ret; |
e2f74f35 | 980 | } |
909a694e | 981 | |
26619804 | 982 | return 0; |
e18f1682 SB |
983 | } |
984 | ||
de1df26b RW |
985 | __weak struct cpufreq_governor *cpufreq_default_governor(void) |
986 | { | |
987 | return NULL; | |
988 | } | |
989 | ||
7f0fa40f | 990 | static int cpufreq_init_policy(struct cpufreq_policy *policy) |
e18f1682 | 991 | { |
6e2c89d1 | 992 | struct cpufreq_governor *gov = NULL; |
e18f1682 | 993 | struct cpufreq_policy new_policy; |
e18f1682 | 994 | |
d5b73cd8 | 995 | memcpy(&new_policy, policy, sizeof(*policy)); |
a27a9ab7 | 996 | |
6e2c89d1 | 997 | /* Update governor of new_policy to the governor used before hotplug */ |
4573237b | 998 | gov = find_governor(policy->last_governor); |
de1df26b | 999 | if (gov) { |
6e2c89d1 | 1000 | pr_debug("Restoring governor %s for cpu %d\n", |
1001 | policy->governor->name, policy->cpu); | |
de1df26b RW |
1002 | } else { |
1003 | gov = cpufreq_default_governor(); | |
1004 | if (!gov) | |
1005 | return -ENODATA; | |
1006 | } | |
6e2c89d1 | 1007 | |
1008 | new_policy.governor = gov; | |
1009 | ||
69030dd1 SP |
1010 | /* Use the default policy if there is no last_policy. */ |
1011 | if (cpufreq_driver->setpolicy) { | |
1012 | if (policy->last_policy) | |
1013 | new_policy.policy = policy->last_policy; | |
1014 | else | |
1015 | cpufreq_parse_governor(gov->name, &new_policy.policy, | |
1016 | NULL); | |
1017 | } | |
ecf7e461 | 1018 | /* set default policy */ |
7f0fa40f | 1019 | return cpufreq_set_policy(policy, &new_policy); |
909a694e DJ |
1020 | } |
1021 | ||
d9612a49 | 1022 | static int cpufreq_add_policy_cpu(struct cpufreq_policy *policy, unsigned int cpu) |
fcf80582 | 1023 | { |
9c0ebcf7 | 1024 | int ret = 0; |
fcf80582 | 1025 | |
bb29ae15 VK |
1026 | /* Has this CPU been taken care of already? */ |
1027 | if (cpumask_test_cpu(cpu, policy->cpus)) | |
1028 | return 0; | |
1029 | ||
49f18560 | 1030 | down_write(&policy->rwsem); |
45482c70 RW |
1031 | if (has_target()) |
1032 | cpufreq_stop_governor(policy); | |
fcf80582 | 1033 | |
fcf80582 | 1034 | cpumask_set_cpu(cpu, policy->cpus); |
2eaa3e2d | 1035 | |
9c0ebcf7 | 1036 | if (has_target()) { |
0a300767 | 1037 | ret = cpufreq_start_governor(policy); |
49f18560 | 1038 | if (ret) |
3de9bdeb | 1039 | pr_err("%s: Failed to start governor\n", __func__); |
820c6ca2 | 1040 | } |
49f18560 VK |
1041 | up_write(&policy->rwsem); |
1042 | return ret; | |
fcf80582 | 1043 | } |
1da177e4 | 1044 | |
11eb69b9 VK |
1045 | static void handle_update(struct work_struct *work) |
1046 | { | |
1047 | struct cpufreq_policy *policy = | |
1048 | container_of(work, struct cpufreq_policy, update); | |
1049 | unsigned int cpu = policy->cpu; | |
1050 | pr_debug("handle_update for cpu %u called\n", cpu); | |
1051 | cpufreq_update_policy(cpu); | |
fcf80582 | 1052 | } |
1da177e4 | 1053 | |
a34e63b1 | 1054 | static struct cpufreq_policy *cpufreq_policy_alloc(unsigned int cpu) |
e9698cc5 SB |
1055 | { |
1056 | struct cpufreq_policy *policy; | |
edd4a893 | 1057 | int ret; |
e9698cc5 SB |
1058 | |
1059 | policy = kzalloc(sizeof(*policy), GFP_KERNEL); | |
1060 | if (!policy) | |
1061 | return NULL; | |
1062 | ||
1063 | if (!alloc_cpumask_var(&policy->cpus, GFP_KERNEL)) | |
1064 | goto err_free_policy; | |
1065 | ||
1066 | if (!zalloc_cpumask_var(&policy->related_cpus, GFP_KERNEL)) | |
1067 | goto err_free_cpumask; | |
1068 | ||
559ed407 RW |
1069 | if (!zalloc_cpumask_var(&policy->real_cpus, GFP_KERNEL)) |
1070 | goto err_free_rcpumask; | |
1071 | ||
edd4a893 VK |
1072 | ret = kobject_init_and_add(&policy->kobj, &ktype_cpufreq, |
1073 | cpufreq_global_kobject, "policy%u", cpu); | |
1074 | if (ret) { | |
1075 | pr_err("%s: failed to init policy->kobj: %d\n", __func__, ret); | |
1076 | goto err_free_real_cpus; | |
1077 | } | |
1078 | ||
c88a1f8b | 1079 | INIT_LIST_HEAD(&policy->policy_list); |
ad7722da | 1080 | init_rwsem(&policy->rwsem); |
12478cf0 SB |
1081 | spin_lock_init(&policy->transition_lock); |
1082 | init_waitqueue_head(&policy->transition_wait); | |
818c5712 VK |
1083 | init_completion(&policy->kobj_unregister); |
1084 | INIT_WORK(&policy->update, handle_update); | |
ad7722da | 1085 | |
a34e63b1 | 1086 | policy->cpu = cpu; |
e9698cc5 SB |
1087 | return policy; |
1088 | ||
edd4a893 VK |
1089 | err_free_real_cpus: |
1090 | free_cpumask_var(policy->real_cpus); | |
2fc3384d VK |
1091 | err_free_rcpumask: |
1092 | free_cpumask_var(policy->related_cpus); | |
e9698cc5 SB |
1093 | err_free_cpumask: |
1094 | free_cpumask_var(policy->cpus); | |
1095 | err_free_policy: | |
1096 | kfree(policy); | |
1097 | ||
1098 | return NULL; | |
1099 | } | |
1100 | ||
f9f41e3e | 1101 | static void cpufreq_policy_put_kobj(struct cpufreq_policy *policy) |
42f921a6 VK |
1102 | { |
1103 | struct kobject *kobj; | |
1104 | struct completion *cmp; | |
1105 | ||
87549141 | 1106 | down_write(&policy->rwsem); |
1aefc75b | 1107 | cpufreq_stats_free_table(policy); |
42f921a6 VK |
1108 | kobj = &policy->kobj; |
1109 | cmp = &policy->kobj_unregister; | |
87549141 | 1110 | up_write(&policy->rwsem); |
42f921a6 VK |
1111 | kobject_put(kobj); |
1112 | ||
1113 | /* | |
1114 | * We need to make sure that the underlying kobj is | |
1115 | * actually not referenced anymore by anybody before we | |
1116 | * proceed with unloading. | |
1117 | */ | |
1118 | pr_debug("waiting for dropping of refcount\n"); | |
1119 | wait_for_completion(cmp); | |
1120 | pr_debug("wait complete\n"); | |
1121 | } | |
1122 | ||
f9f41e3e | 1123 | static void cpufreq_policy_free(struct cpufreq_policy *policy) |
e9698cc5 | 1124 | { |
988bed09 VK |
1125 | unsigned long flags; |
1126 | int cpu; | |
1127 | ||
1128 | /* Remove policy from list */ | |
1129 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
1130 | list_del(&policy->policy_list); | |
1131 | ||
1132 | for_each_cpu(cpu, policy->related_cpus) | |
1133 | per_cpu(cpufreq_cpu_data, cpu) = NULL; | |
1134 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1135 | ||
f9f41e3e | 1136 | cpufreq_policy_put_kobj(policy); |
559ed407 | 1137 | free_cpumask_var(policy->real_cpus); |
e9698cc5 SB |
1138 | free_cpumask_var(policy->related_cpus); |
1139 | free_cpumask_var(policy->cpus); | |
1140 | kfree(policy); | |
1141 | } | |
1142 | ||
0b275352 | 1143 | static int cpufreq_online(unsigned int cpu) |
1da177e4 | 1144 | { |
7f0c020a | 1145 | struct cpufreq_policy *policy; |
194d99c7 | 1146 | bool new_policy; |
1da177e4 | 1147 | unsigned long flags; |
0b275352 RW |
1148 | unsigned int j; |
1149 | int ret; | |
87549141 | 1150 | |
0b275352 | 1151 | pr_debug("%s: bringing CPU%u online\n", __func__, cpu); |
6eed9404 | 1152 | |
bb29ae15 | 1153 | /* Check if this CPU already has a policy to manage it */ |
9104bb26 | 1154 | policy = per_cpu(cpufreq_cpu_data, cpu); |
11ce707e | 1155 | if (policy) { |
9104bb26 | 1156 | WARN_ON(!cpumask_test_cpu(cpu, policy->related_cpus)); |
11ce707e | 1157 | if (!policy_is_inactive(policy)) |
d9612a49 | 1158 | return cpufreq_add_policy_cpu(policy, cpu); |
1da177e4 | 1159 | |
11ce707e | 1160 | /* This is the only online CPU for the policy. Start over. */ |
194d99c7 | 1161 | new_policy = false; |
11ce707e RW |
1162 | down_write(&policy->rwsem); |
1163 | policy->cpu = cpu; | |
1164 | policy->governor = NULL; | |
1165 | up_write(&policy->rwsem); | |
1166 | } else { | |
194d99c7 | 1167 | new_policy = true; |
a34e63b1 | 1168 | policy = cpufreq_policy_alloc(cpu); |
72368d12 | 1169 | if (!policy) |
d4d854d6 | 1170 | return -ENOMEM; |
72368d12 | 1171 | } |
0d66b91e | 1172 | |
835481d9 | 1173 | cpumask_copy(policy->cpus, cpumask_of(cpu)); |
1da177e4 | 1174 | |
1da177e4 LT |
1175 | /* call driver. From then on the cpufreq must be able |
1176 | * to accept all calls to ->verify and ->setpolicy for this CPU | |
1177 | */ | |
1c3d85dd | 1178 | ret = cpufreq_driver->init(policy); |
1da177e4 | 1179 | if (ret) { |
2d06d8c4 | 1180 | pr_debug("initialization failed\n"); |
8101f997 | 1181 | goto out_free_policy; |
1da177e4 | 1182 | } |
643ae6e8 | 1183 | |
6d4e81ed TV |
1184 | down_write(&policy->rwsem); |
1185 | ||
194d99c7 | 1186 | if (new_policy) { |
4d1f3a5b | 1187 | /* related_cpus should at least include policy->cpus. */ |
0998a03a | 1188 | cpumask_copy(policy->related_cpus, policy->cpus); |
4d1f3a5b | 1189 | } |
559ed407 | 1190 | |
5a7e56a5 VK |
1191 | /* |
1192 | * affected cpus must always be the one, which are online. We aren't | |
1193 | * managing offline cpus here. | |
1194 | */ | |
1195 | cpumask_and(policy->cpus, policy->cpus, cpu_online_mask); | |
1196 | ||
194d99c7 | 1197 | if (new_policy) { |
5a7e56a5 VK |
1198 | policy->user_policy.min = policy->min; |
1199 | policy->user_policy.max = policy->max; | |
6d4e81ed | 1200 | |
2f0ba790 | 1201 | for_each_cpu(j, policy->related_cpus) { |
988bed09 | 1202 | per_cpu(cpufreq_cpu_data, j) = policy; |
2f0ba790 RW |
1203 | add_cpu_dev_symlink(policy, j); |
1204 | } | |
ff010472 VK |
1205 | } else { |
1206 | policy->min = policy->user_policy.min; | |
1207 | policy->max = policy->user_policy.max; | |
988bed09 | 1208 | } |
652ed95d | 1209 | |
2ed99e39 | 1210 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
da60ce9f VK |
1211 | policy->cur = cpufreq_driver->get(policy->cpu); |
1212 | if (!policy->cur) { | |
1213 | pr_err("%s: ->get() failed\n", __func__); | |
8101f997 | 1214 | goto out_exit_policy; |
da60ce9f VK |
1215 | } |
1216 | } | |
1217 | ||
d3916691 VK |
1218 | /* |
1219 | * Sometimes boot loaders set CPU frequency to a value outside of | |
1220 | * frequency table present with cpufreq core. In such cases CPU might be | |
1221 | * unstable if it has to run on that frequency for long duration of time | |
1222 | * and so its better to set it to a frequency which is specified in | |
1223 | * freq-table. This also makes cpufreq stats inconsistent as | |
1224 | * cpufreq-stats would fail to register because current frequency of CPU | |
1225 | * isn't found in freq-table. | |
1226 | * | |
1227 | * Because we don't want this change to effect boot process badly, we go | |
1228 | * for the next freq which is >= policy->cur ('cur' must be set by now, | |
1229 | * otherwise we will end up setting freq to lowest of the table as 'cur' | |
1230 | * is initialized to zero). | |
1231 | * | |
1232 | * We are passing target-freq as "policy->cur - 1" otherwise | |
1233 | * __cpufreq_driver_target() would simply fail, as policy->cur will be | |
1234 | * equal to target-freq. | |
1235 | */ | |
1236 | if ((cpufreq_driver->flags & CPUFREQ_NEED_INITIAL_FREQ_CHECK) | |
1237 | && has_target()) { | |
1238 | /* Are we running at unknown frequency ? */ | |
1239 | ret = cpufreq_frequency_table_get_index(policy, policy->cur); | |
1240 | if (ret == -EINVAL) { | |
1241 | /* Warn user and fix it */ | |
1242 | pr_warn("%s: CPU%d: Running at unlisted freq: %u KHz\n", | |
1243 | __func__, policy->cpu, policy->cur); | |
1244 | ret = __cpufreq_driver_target(policy, policy->cur - 1, | |
1245 | CPUFREQ_RELATION_L); | |
1246 | ||
1247 | /* | |
1248 | * Reaching here after boot in a few seconds may not | |
1249 | * mean that system will remain stable at "unknown" | |
1250 | * frequency for longer duration. Hence, a BUG_ON(). | |
1251 | */ | |
1252 | BUG_ON(ret); | |
1253 | pr_warn("%s: CPU%d: Unlisted initial frequency changed to: %u KHz\n", | |
1254 | __func__, policy->cpu, policy->cur); | |
1255 | } | |
1256 | } | |
1257 | ||
194d99c7 | 1258 | if (new_policy) { |
d9612a49 | 1259 | ret = cpufreq_add_dev_interface(policy); |
a82fab29 | 1260 | if (ret) |
8101f997 | 1261 | goto out_exit_policy; |
1aefc75b RW |
1262 | |
1263 | cpufreq_stats_create_table(policy); | |
8ff69732 | 1264 | |
988bed09 VK |
1265 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1266 | list_add(&policy->policy_list, &cpufreq_policy_list); | |
1267 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1268 | } | |
9515f4d6 | 1269 | |
7f0fa40f VK |
1270 | ret = cpufreq_init_policy(policy); |
1271 | if (ret) { | |
1272 | pr_err("%s: Failed to initialize policy for cpu: %d (%d)\n", | |
1273 | __func__, cpu, ret); | |
194d99c7 RW |
1274 | /* cpufreq_policy_free() will notify based on this */ |
1275 | new_policy = false; | |
1276 | goto out_exit_policy; | |
08fd8c1c | 1277 | } |
e18f1682 | 1278 | |
4e97b631 | 1279 | up_write(&policy->rwsem); |
08fd8c1c | 1280 | |
038c5b3e | 1281 | kobject_uevent(&policy->kobj, KOBJ_ADD); |
7c45cf31 | 1282 | |
7c45cf31 VK |
1283 | /* Callback for handling stuff after policy is ready */ |
1284 | if (cpufreq_driver->ready) | |
1285 | cpufreq_driver->ready(policy); | |
1286 | ||
2d06d8c4 | 1287 | pr_debug("initialization complete\n"); |
87c32271 | 1288 | |
1da177e4 LT |
1289 | return 0; |
1290 | ||
8101f997 | 1291 | out_exit_policy: |
7106e02b PB |
1292 | up_write(&policy->rwsem); |
1293 | ||
da60ce9f VK |
1294 | if (cpufreq_driver->exit) |
1295 | cpufreq_driver->exit(policy); | |
2f0ba790 RW |
1296 | |
1297 | for_each_cpu(j, policy->real_cpus) | |
1298 | remove_cpu_dev_symlink(policy, get_cpu_device(j)); | |
1299 | ||
8101f997 | 1300 | out_free_policy: |
f9f41e3e | 1301 | cpufreq_policy_free(policy); |
1da177e4 LT |
1302 | return ret; |
1303 | } | |
1304 | ||
0b275352 RW |
1305 | /** |
1306 | * cpufreq_add_dev - the cpufreq interface for a CPU device. | |
1307 | * @dev: CPU device. | |
1308 | * @sif: Subsystem interface structure pointer (not used) | |
1309 | */ | |
1310 | static int cpufreq_add_dev(struct device *dev, struct subsys_interface *sif) | |
1311 | { | |
a794d613 | 1312 | struct cpufreq_policy *policy; |
0b275352 | 1313 | unsigned cpu = dev->id; |
26619804 | 1314 | int ret; |
0b275352 RW |
1315 | |
1316 | dev_dbg(dev, "%s: adding CPU%u\n", __func__, cpu); | |
1317 | ||
26619804 VK |
1318 | if (cpu_online(cpu)) { |
1319 | ret = cpufreq_online(cpu); | |
1320 | if (ret) | |
1321 | return ret; | |
1322 | } | |
0b275352 | 1323 | |
26619804 | 1324 | /* Create sysfs link on CPU registration */ |
a794d613 | 1325 | policy = per_cpu(cpufreq_cpu_data, cpu); |
2f0ba790 RW |
1326 | if (policy) |
1327 | add_cpu_dev_symlink(policy, cpu); | |
26619804 | 1328 | |
2f0ba790 | 1329 | return 0; |
1da177e4 LT |
1330 | } |
1331 | ||
27622b06 | 1332 | static int cpufreq_offline(unsigned int cpu) |
1da177e4 | 1333 | { |
3a3e9e06 | 1334 | struct cpufreq_policy *policy; |
69cee714 | 1335 | int ret; |
1da177e4 | 1336 | |
b8eed8af | 1337 | pr_debug("%s: unregistering CPU %u\n", __func__, cpu); |
1da177e4 | 1338 | |
988bed09 | 1339 | policy = cpufreq_cpu_get_raw(cpu); |
3a3e9e06 | 1340 | if (!policy) { |
b8eed8af | 1341 | pr_debug("%s: No cpu_data found\n", __func__); |
27622b06 | 1342 | return 0; |
1da177e4 | 1343 | } |
1da177e4 | 1344 | |
49f18560 | 1345 | down_write(&policy->rwsem); |
45482c70 RW |
1346 | if (has_target()) |
1347 | cpufreq_stop_governor(policy); | |
1da177e4 | 1348 | |
9591becb | 1349 | cpumask_clear_cpu(cpu, policy->cpus); |
4573237b | 1350 | |
9591becb VK |
1351 | if (policy_is_inactive(policy)) { |
1352 | if (has_target()) | |
1353 | strncpy(policy->last_governor, policy->governor->name, | |
1354 | CPUFREQ_NAME_LEN); | |
69030dd1 SP |
1355 | else |
1356 | policy->last_policy = policy->policy; | |
9591becb VK |
1357 | } else if (cpu == policy->cpu) { |
1358 | /* Nominate new CPU */ | |
1359 | policy->cpu = cpumask_any(policy->cpus); | |
1360 | } | |
084f3493 | 1361 | |
9591becb VK |
1362 | /* Start governor again for active policy */ |
1363 | if (!policy_is_inactive(policy)) { | |
1364 | if (has_target()) { | |
0a300767 | 1365 | ret = cpufreq_start_governor(policy); |
9591becb VK |
1366 | if (ret) |
1367 | pr_err("%s: Failed to start governor\n", __func__); | |
1368 | } | |
cedb70af | 1369 | |
49f18560 | 1370 | goto unlock; |
cedb70af SB |
1371 | } |
1372 | ||
69cee714 VK |
1373 | if (cpufreq_driver->stop_cpu) |
1374 | cpufreq_driver->stop_cpu(policy); | |
87549141 | 1375 | |
36be3418 RW |
1376 | if (has_target()) |
1377 | cpufreq_exit_governor(policy); | |
1da177e4 | 1378 | |
87549141 VK |
1379 | /* |
1380 | * Perform the ->exit() even during light-weight tear-down, | |
1381 | * since this is a core component, and is essential for the | |
1382 | * subsequent light-weight ->init() to succeed. | |
1383 | */ | |
55582bcc | 1384 | if (cpufreq_driver->exit) { |
87549141 | 1385 | cpufreq_driver->exit(policy); |
55582bcc SP |
1386 | policy->freq_table = NULL; |
1387 | } | |
49f18560 VK |
1388 | |
1389 | unlock: | |
1390 | up_write(&policy->rwsem); | |
27622b06 | 1391 | return 0; |
1da177e4 LT |
1392 | } |
1393 | ||
cedb70af | 1394 | /** |
27a862e9 | 1395 | * cpufreq_remove_dev - remove a CPU device |
cedb70af SB |
1396 | * |
1397 | * Removes the cpufreq interface for a CPU device. | |
cedb70af | 1398 | */ |
71db87ba | 1399 | static void cpufreq_remove_dev(struct device *dev, struct subsys_interface *sif) |
5a01f2e8 | 1400 | { |
8a25a2fd | 1401 | unsigned int cpu = dev->id; |
559ed407 | 1402 | struct cpufreq_policy *policy = per_cpu(cpufreq_cpu_data, cpu); |
87549141 | 1403 | |
559ed407 | 1404 | if (!policy) |
1af115d6 | 1405 | return; |
87549141 | 1406 | |
69cee714 VK |
1407 | if (cpu_online(cpu)) |
1408 | cpufreq_offline(cpu); | |
87549141 | 1409 | |
559ed407 | 1410 | cpumask_clear_cpu(cpu, policy->real_cpus); |
26619804 | 1411 | remove_cpu_dev_symlink(policy, dev); |
87549141 | 1412 | |
f344dae0 | 1413 | if (cpumask_empty(policy->real_cpus)) |
f9f41e3e | 1414 | cpufreq_policy_free(policy); |
5a01f2e8 VP |
1415 | } |
1416 | ||
1da177e4 | 1417 | /** |
bb176f7d VK |
1418 | * cpufreq_out_of_sync - If actual and saved CPU frequency differs, we're |
1419 | * in deep trouble. | |
a1e1dc41 | 1420 | * @policy: policy managing CPUs |
1da177e4 LT |
1421 | * @new_freq: CPU frequency the CPU actually runs at |
1422 | * | |
29464f28 DJ |
1423 | * We adjust to current frequency first, and need to clean up later. |
1424 | * So either call to cpufreq_update_policy() or schedule handle_update()). | |
1da177e4 | 1425 | */ |
a1e1dc41 | 1426 | static void cpufreq_out_of_sync(struct cpufreq_policy *policy, |
e08f5f5b | 1427 | unsigned int new_freq) |
1da177e4 LT |
1428 | { |
1429 | struct cpufreq_freqs freqs; | |
b43a7ffb | 1430 | |
e837f9b5 | 1431 | pr_debug("Warning: CPU frequency out of sync: cpufreq and timing core thinks of %u, is %u kHz\n", |
a1e1dc41 | 1432 | policy->cur, new_freq); |
1da177e4 | 1433 | |
a1e1dc41 | 1434 | freqs.old = policy->cur; |
1da177e4 | 1435 | freqs.new = new_freq; |
b43a7ffb | 1436 | |
8fec051e VK |
1437 | cpufreq_freq_transition_begin(policy, &freqs); |
1438 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1da177e4 LT |
1439 | } |
1440 | ||
32ee8c3e | 1441 | /** |
4ab70df4 | 1442 | * cpufreq_quick_get - get the CPU frequency (in kHz) from policy->cur |
95235ca2 VP |
1443 | * @cpu: CPU number |
1444 | * | |
1445 | * This is the last known freq, without actually getting it from the driver. | |
1446 | * Return value will be same as what is shown in scaling_cur_freq in sysfs. | |
1447 | */ | |
1448 | unsigned int cpufreq_quick_get(unsigned int cpu) | |
1449 | { | |
9e21ba8b | 1450 | struct cpufreq_policy *policy; |
e08f5f5b | 1451 | unsigned int ret_freq = 0; |
c75361c0 | 1452 | unsigned long flags; |
95235ca2 | 1453 | |
c75361c0 RC |
1454 | read_lock_irqsave(&cpufreq_driver_lock, flags); |
1455 | ||
1456 | if (cpufreq_driver && cpufreq_driver->setpolicy && cpufreq_driver->get) { | |
1457 | ret_freq = cpufreq_driver->get(cpu); | |
1458 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
1459 | return ret_freq; | |
1460 | } | |
1461 | ||
1462 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
9e21ba8b DB |
1463 | |
1464 | policy = cpufreq_cpu_get(cpu); | |
95235ca2 | 1465 | if (policy) { |
e08f5f5b | 1466 | ret_freq = policy->cur; |
95235ca2 VP |
1467 | cpufreq_cpu_put(policy); |
1468 | } | |
1469 | ||
4d34a67d | 1470 | return ret_freq; |
95235ca2 VP |
1471 | } |
1472 | EXPORT_SYMBOL(cpufreq_quick_get); | |
1473 | ||
3d737108 JB |
1474 | /** |
1475 | * cpufreq_quick_get_max - get the max reported CPU frequency for this CPU | |
1476 | * @cpu: CPU number | |
1477 | * | |
1478 | * Just return the max possible frequency for a given CPU. | |
1479 | */ | |
1480 | unsigned int cpufreq_quick_get_max(unsigned int cpu) | |
1481 | { | |
1482 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); | |
1483 | unsigned int ret_freq = 0; | |
1484 | ||
1485 | if (policy) { | |
1486 | ret_freq = policy->max; | |
1487 | cpufreq_cpu_put(policy); | |
1488 | } | |
1489 | ||
1490 | return ret_freq; | |
1491 | } | |
1492 | EXPORT_SYMBOL(cpufreq_quick_get_max); | |
1493 | ||
d92d50a4 | 1494 | static unsigned int __cpufreq_get(struct cpufreq_policy *policy) |
1da177e4 | 1495 | { |
e08f5f5b | 1496 | unsigned int ret_freq = 0; |
5800043b | 1497 | |
1c3d85dd | 1498 | if (!cpufreq_driver->get) |
4d34a67d | 1499 | return ret_freq; |
1da177e4 | 1500 | |
d92d50a4 | 1501 | ret_freq = cpufreq_driver->get(policy->cpu); |
1da177e4 | 1502 | |
b7898fda RW |
1503 | /* |
1504 | * Updating inactive policies is invalid, so avoid doing that. Also | |
1505 | * if fast frequency switching is used with the given policy, the check | |
1506 | * against policy->cur is pointless, so skip it in that case too. | |
1507 | */ | |
1508 | if (unlikely(policy_is_inactive(policy)) || policy->fast_switch_enabled) | |
11e584cf VK |
1509 | return ret_freq; |
1510 | ||
e08f5f5b | 1511 | if (ret_freq && policy->cur && |
1c3d85dd | 1512 | !(cpufreq_driver->flags & CPUFREQ_CONST_LOOPS)) { |
e08f5f5b GS |
1513 | /* verify no discrepancy between actual and |
1514 | saved value exists */ | |
1515 | if (unlikely(ret_freq != policy->cur)) { | |
a1e1dc41 | 1516 | cpufreq_out_of_sync(policy, ret_freq); |
1da177e4 LT |
1517 | schedule_work(&policy->update); |
1518 | } | |
1519 | } | |
1520 | ||
4d34a67d | 1521 | return ret_freq; |
5a01f2e8 | 1522 | } |
1da177e4 | 1523 | |
5a01f2e8 VP |
1524 | /** |
1525 | * cpufreq_get - get the current CPU frequency (in kHz) | |
1526 | * @cpu: CPU number | |
1527 | * | |
1528 | * Get the CPU current (static) CPU frequency | |
1529 | */ | |
1530 | unsigned int cpufreq_get(unsigned int cpu) | |
1531 | { | |
999976e0 | 1532 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
5a01f2e8 | 1533 | unsigned int ret_freq = 0; |
5a01f2e8 | 1534 | |
999976e0 AP |
1535 | if (policy) { |
1536 | down_read(&policy->rwsem); | |
182e36af RW |
1537 | |
1538 | if (!policy_is_inactive(policy)) | |
1539 | ret_freq = __cpufreq_get(policy); | |
1540 | ||
999976e0 | 1541 | up_read(&policy->rwsem); |
5a01f2e8 | 1542 | |
999976e0 AP |
1543 | cpufreq_cpu_put(policy); |
1544 | } | |
6eed9404 | 1545 | |
4d34a67d | 1546 | return ret_freq; |
1da177e4 LT |
1547 | } |
1548 | EXPORT_SYMBOL(cpufreq_get); | |
1549 | ||
999f5729 RW |
1550 | static unsigned int cpufreq_update_current_freq(struct cpufreq_policy *policy) |
1551 | { | |
1552 | unsigned int new_freq; | |
1553 | ||
1554 | new_freq = cpufreq_driver->get(policy->cpu); | |
1555 | if (!new_freq) | |
1556 | return 0; | |
1557 | ||
1558 | if (!policy->cur) { | |
1559 | pr_debug("cpufreq: Driver did not initialize current freq\n"); | |
1560 | policy->cur = new_freq; | |
1561 | } else if (policy->cur != new_freq && has_target()) { | |
1562 | cpufreq_out_of_sync(policy, new_freq); | |
1563 | } | |
1564 | ||
1565 | return new_freq; | |
1566 | } | |
1567 | ||
8a25a2fd KS |
1568 | static struct subsys_interface cpufreq_interface = { |
1569 | .name = "cpufreq", | |
1570 | .subsys = &cpu_subsys, | |
1571 | .add_dev = cpufreq_add_dev, | |
1572 | .remove_dev = cpufreq_remove_dev, | |
e00e56df RW |
1573 | }; |
1574 | ||
e28867ea VK |
1575 | /* |
1576 | * In case platform wants some specific frequency to be configured | |
1577 | * during suspend.. | |
1578 | */ | |
1579 | int cpufreq_generic_suspend(struct cpufreq_policy *policy) | |
1580 | { | |
1581 | int ret; | |
1582 | ||
1583 | if (!policy->suspend_freq) { | |
201f3716 BZ |
1584 | pr_debug("%s: suspend_freq not defined\n", __func__); |
1585 | return 0; | |
e28867ea VK |
1586 | } |
1587 | ||
1588 | pr_debug("%s: Setting suspend-freq: %u\n", __func__, | |
1589 | policy->suspend_freq); | |
1590 | ||
1591 | ret = __cpufreq_driver_target(policy, policy->suspend_freq, | |
1592 | CPUFREQ_RELATION_H); | |
1593 | if (ret) | |
1594 | pr_err("%s: unable to set suspend-freq: %u. err: %d\n", | |
1595 | __func__, policy->suspend_freq, ret); | |
1596 | ||
1597 | return ret; | |
1598 | } | |
1599 | EXPORT_SYMBOL(cpufreq_generic_suspend); | |
1600 | ||
42d4dc3f | 1601 | /** |
2f0aea93 | 1602 | * cpufreq_suspend() - Suspend CPUFreq governors |
e00e56df | 1603 | * |
2f0aea93 VK |
1604 | * Called during system wide Suspend/Hibernate cycles for suspending governors |
1605 | * as some platforms can't change frequency after this point in suspend cycle. | |
1606 | * Because some of the devices (like: i2c, regulators, etc) they use for | |
1607 | * changing frequency are suspended quickly after this point. | |
42d4dc3f | 1608 | */ |
2f0aea93 | 1609 | void cpufreq_suspend(void) |
42d4dc3f | 1610 | { |
3a3e9e06 | 1611 | struct cpufreq_policy *policy; |
42d4dc3f | 1612 | |
2f0aea93 VK |
1613 | if (!cpufreq_driver) |
1614 | return; | |
42d4dc3f | 1615 | |
ba41e1bc | 1616 | if (!has_target() && !cpufreq_driver->suspend) |
b1b12bab | 1617 | goto suspend; |
42d4dc3f | 1618 | |
2f0aea93 VK |
1619 | pr_debug("%s: Suspending Governors\n", __func__); |
1620 | ||
f963735a | 1621 | for_each_active_policy(policy) { |
ba41e1bc RW |
1622 | if (has_target()) { |
1623 | down_write(&policy->rwsem); | |
45482c70 | 1624 | cpufreq_stop_governor(policy); |
ba41e1bc | 1625 | up_write(&policy->rwsem); |
ba41e1bc RW |
1626 | } |
1627 | ||
1628 | if (cpufreq_driver->suspend && cpufreq_driver->suspend(policy)) | |
2f0aea93 VK |
1629 | pr_err("%s: Failed to suspend driver: %p\n", __func__, |
1630 | policy); | |
42d4dc3f | 1631 | } |
b1b12bab VK |
1632 | |
1633 | suspend: | |
1634 | cpufreq_suspended = true; | |
42d4dc3f BH |
1635 | } |
1636 | ||
1da177e4 | 1637 | /** |
2f0aea93 | 1638 | * cpufreq_resume() - Resume CPUFreq governors |
1da177e4 | 1639 | * |
2f0aea93 VK |
1640 | * Called during system wide Suspend/Hibernate cycle for resuming governors that |
1641 | * are suspended with cpufreq_suspend(). | |
1da177e4 | 1642 | */ |
2f0aea93 | 1643 | void cpufreq_resume(void) |
1da177e4 | 1644 | { |
3a3e9e06 | 1645 | struct cpufreq_policy *policy; |
49f18560 | 1646 | int ret; |
1da177e4 | 1647 | |
2f0aea93 VK |
1648 | if (!cpufreq_driver) |
1649 | return; | |
1da177e4 | 1650 | |
8e30444e LT |
1651 | cpufreq_suspended = false; |
1652 | ||
ba41e1bc | 1653 | if (!has_target() && !cpufreq_driver->resume) |
e00e56df | 1654 | return; |
1da177e4 | 1655 | |
2f0aea93 | 1656 | pr_debug("%s: Resuming Governors\n", __func__); |
1da177e4 | 1657 | |
f963735a | 1658 | for_each_active_policy(policy) { |
49f18560 | 1659 | if (cpufreq_driver->resume && cpufreq_driver->resume(policy)) { |
0c5aa405 VK |
1660 | pr_err("%s: Failed to resume driver: %p\n", __func__, |
1661 | policy); | |
ba41e1bc | 1662 | } else if (has_target()) { |
49f18560 | 1663 | down_write(&policy->rwsem); |
0a300767 | 1664 | ret = cpufreq_start_governor(policy); |
49f18560 VK |
1665 | up_write(&policy->rwsem); |
1666 | ||
1667 | if (ret) | |
1668 | pr_err("%s: Failed to start governor for policy: %p\n", | |
1669 | __func__, policy); | |
1670 | } | |
2f0aea93 VK |
1671 | } |
1672 | } | |
1da177e4 | 1673 | |
9d95046e BP |
1674 | /** |
1675 | * cpufreq_get_current_driver - return current driver's name | |
1676 | * | |
1677 | * Return the name string of the currently loaded cpufreq driver | |
1678 | * or NULL, if none. | |
1679 | */ | |
1680 | const char *cpufreq_get_current_driver(void) | |
1681 | { | |
1c3d85dd RW |
1682 | if (cpufreq_driver) |
1683 | return cpufreq_driver->name; | |
1684 | ||
1685 | return NULL; | |
9d95046e BP |
1686 | } |
1687 | EXPORT_SYMBOL_GPL(cpufreq_get_current_driver); | |
1da177e4 | 1688 | |
51315cdf TP |
1689 | /** |
1690 | * cpufreq_get_driver_data - return current driver data | |
1691 | * | |
1692 | * Return the private data of the currently loaded cpufreq | |
1693 | * driver, or NULL if no cpufreq driver is loaded. | |
1694 | */ | |
1695 | void *cpufreq_get_driver_data(void) | |
1696 | { | |
1697 | if (cpufreq_driver) | |
1698 | return cpufreq_driver->driver_data; | |
1699 | ||
1700 | return NULL; | |
1701 | } | |
1702 | EXPORT_SYMBOL_GPL(cpufreq_get_driver_data); | |
1703 | ||
1da177e4 LT |
1704 | /********************************************************************* |
1705 | * NOTIFIER LISTS INTERFACE * | |
1706 | *********************************************************************/ | |
1707 | ||
1708 | /** | |
1709 | * cpufreq_register_notifier - register a driver with cpufreq | |
1710 | * @nb: notifier function to register | |
1711 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER | |
1712 | * | |
32ee8c3e | 1713 | * Add a driver to one of two lists: either a list of drivers that |
1da177e4 LT |
1714 | * are notified about clock rate changes (once before and once after |
1715 | * the transition), or a list of drivers that are notified about | |
1716 | * changes in cpufreq policy. | |
1717 | * | |
1718 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1719 | * blocking_notifier_chain_register. |
1da177e4 LT |
1720 | */ |
1721 | int cpufreq_register_notifier(struct notifier_block *nb, unsigned int list) | |
1722 | { | |
1723 | int ret; | |
1724 | ||
d5aaffa9 DB |
1725 | if (cpufreq_disabled()) |
1726 | return -EINVAL; | |
1727 | ||
74212ca4 CEB |
1728 | WARN_ON(!init_cpufreq_transition_notifier_list_called); |
1729 | ||
1da177e4 LT |
1730 | switch (list) { |
1731 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1732 | mutex_lock(&cpufreq_fast_switch_lock); |
1733 | ||
1734 | if (cpufreq_fast_switch_count > 0) { | |
1735 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1736 | return -EBUSY; | |
1737 | } | |
b4dfdbb3 | 1738 | ret = srcu_notifier_chain_register( |
e041c683 | 1739 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1740 | if (!ret) |
1741 | cpufreq_fast_switch_count--; | |
1742 | ||
1743 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1744 | break; |
1745 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1746 | ret = blocking_notifier_chain_register( |
1747 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1748 | break; |
1749 | default: | |
1750 | ret = -EINVAL; | |
1751 | } | |
1da177e4 LT |
1752 | |
1753 | return ret; | |
1754 | } | |
1755 | EXPORT_SYMBOL(cpufreq_register_notifier); | |
1756 | ||
1da177e4 LT |
1757 | /** |
1758 | * cpufreq_unregister_notifier - unregister a driver with cpufreq | |
1759 | * @nb: notifier block to be unregistered | |
bb176f7d | 1760 | * @list: CPUFREQ_TRANSITION_NOTIFIER or CPUFREQ_POLICY_NOTIFIER |
1da177e4 LT |
1761 | * |
1762 | * Remove a driver from the CPU frequency notifier list. | |
1763 | * | |
1764 | * This function may sleep, and has the same return conditions as | |
e041c683 | 1765 | * blocking_notifier_chain_unregister. |
1da177e4 LT |
1766 | */ |
1767 | int cpufreq_unregister_notifier(struct notifier_block *nb, unsigned int list) | |
1768 | { | |
1769 | int ret; | |
1770 | ||
d5aaffa9 DB |
1771 | if (cpufreq_disabled()) |
1772 | return -EINVAL; | |
1773 | ||
1da177e4 LT |
1774 | switch (list) { |
1775 | case CPUFREQ_TRANSITION_NOTIFIER: | |
b7898fda RW |
1776 | mutex_lock(&cpufreq_fast_switch_lock); |
1777 | ||
b4dfdbb3 | 1778 | ret = srcu_notifier_chain_unregister( |
e041c683 | 1779 | &cpufreq_transition_notifier_list, nb); |
b7898fda RW |
1780 | if (!ret && !WARN_ON(cpufreq_fast_switch_count >= 0)) |
1781 | cpufreq_fast_switch_count++; | |
1782 | ||
1783 | mutex_unlock(&cpufreq_fast_switch_lock); | |
1da177e4 LT |
1784 | break; |
1785 | case CPUFREQ_POLICY_NOTIFIER: | |
e041c683 AS |
1786 | ret = blocking_notifier_chain_unregister( |
1787 | &cpufreq_policy_notifier_list, nb); | |
1da177e4 LT |
1788 | break; |
1789 | default: | |
1790 | ret = -EINVAL; | |
1791 | } | |
1da177e4 LT |
1792 | |
1793 | return ret; | |
1794 | } | |
1795 | EXPORT_SYMBOL(cpufreq_unregister_notifier); | |
1796 | ||
1797 | ||
1798 | /********************************************************************* | |
1799 | * GOVERNORS * | |
1800 | *********************************************************************/ | |
1801 | ||
b7898fda RW |
1802 | /** |
1803 | * cpufreq_driver_fast_switch - Carry out a fast CPU frequency switch. | |
1804 | * @policy: cpufreq policy to switch the frequency for. | |
1805 | * @target_freq: New frequency to set (may be approximate). | |
1806 | * | |
1807 | * Carry out a fast frequency switch without sleeping. | |
1808 | * | |
1809 | * The driver's ->fast_switch() callback invoked by this function must be | |
1810 | * suitable for being called from within RCU-sched read-side critical sections | |
1811 | * and it is expected to select the minimum available frequency greater than or | |
1812 | * equal to @target_freq (CPUFREQ_RELATION_L). | |
1813 | * | |
1814 | * This function must not be called if policy->fast_switch_enabled is unset. | |
1815 | * | |
1816 | * Governors calling this function must guarantee that it will never be invoked | |
1817 | * twice in parallel for the same policy and that it will never be called in | |
1818 | * parallel with either ->target() or ->target_index() for the same policy. | |
1819 | * | |
1820 | * If CPUFREQ_ENTRY_INVALID is returned by the driver's ->fast_switch() | |
1821 | * callback to indicate an error condition, the hardware configuration must be | |
1822 | * preserved. | |
1823 | */ | |
1824 | unsigned int cpufreq_driver_fast_switch(struct cpufreq_policy *policy, | |
1825 | unsigned int target_freq) | |
1826 | { | |
b9af6948 | 1827 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
b7898fda RW |
1828 | |
1829 | return cpufreq_driver->fast_switch(policy, target_freq); | |
1830 | } | |
1831 | EXPORT_SYMBOL_GPL(cpufreq_driver_fast_switch); | |
1832 | ||
1c03a2d0 VK |
1833 | /* Must set freqs->new to intermediate frequency */ |
1834 | static int __target_intermediate(struct cpufreq_policy *policy, | |
1835 | struct cpufreq_freqs *freqs, int index) | |
1836 | { | |
1837 | int ret; | |
1838 | ||
1839 | freqs->new = cpufreq_driver->get_intermediate(policy, index); | |
1840 | ||
1841 | /* We don't need to switch to intermediate freq */ | |
1842 | if (!freqs->new) | |
1843 | return 0; | |
1844 | ||
1845 | pr_debug("%s: cpu: %d, switching to intermediate freq: oldfreq: %u, intermediate freq: %u\n", | |
1846 | __func__, policy->cpu, freqs->old, freqs->new); | |
1847 | ||
1848 | cpufreq_freq_transition_begin(policy, freqs); | |
1849 | ret = cpufreq_driver->target_intermediate(policy, index); | |
1850 | cpufreq_freq_transition_end(policy, freqs, ret); | |
1851 | ||
1852 | if (ret) | |
1853 | pr_err("%s: Failed to change to intermediate frequency: %d\n", | |
1854 | __func__, ret); | |
1855 | ||
1856 | return ret; | |
1857 | } | |
1858 | ||
23727845 | 1859 | static int __target_index(struct cpufreq_policy *policy, int index) |
8d65775d | 1860 | { |
1c03a2d0 VK |
1861 | struct cpufreq_freqs freqs = {.old = policy->cur, .flags = 0}; |
1862 | unsigned int intermediate_freq = 0; | |
23727845 | 1863 | unsigned int newfreq = policy->freq_table[index].frequency; |
8d65775d VK |
1864 | int retval = -EINVAL; |
1865 | bool notify; | |
1866 | ||
23727845 VK |
1867 | if (newfreq == policy->cur) |
1868 | return 0; | |
1869 | ||
8d65775d | 1870 | notify = !(cpufreq_driver->flags & CPUFREQ_ASYNC_NOTIFICATION); |
8d65775d | 1871 | if (notify) { |
1c03a2d0 VK |
1872 | /* Handle switching to intermediate frequency */ |
1873 | if (cpufreq_driver->get_intermediate) { | |
1874 | retval = __target_intermediate(policy, &freqs, index); | |
1875 | if (retval) | |
1876 | return retval; | |
1877 | ||
1878 | intermediate_freq = freqs.new; | |
1879 | /* Set old freq to intermediate */ | |
1880 | if (intermediate_freq) | |
1881 | freqs.old = freqs.new; | |
1882 | } | |
8d65775d | 1883 | |
23727845 | 1884 | freqs.new = newfreq; |
8d65775d VK |
1885 | pr_debug("%s: cpu: %d, oldfreq: %u, new freq: %u\n", |
1886 | __func__, policy->cpu, freqs.old, freqs.new); | |
1887 | ||
1888 | cpufreq_freq_transition_begin(policy, &freqs); | |
1889 | } | |
1890 | ||
1891 | retval = cpufreq_driver->target_index(policy, index); | |
1892 | if (retval) | |
1893 | pr_err("%s: Failed to change cpu frequency: %d\n", __func__, | |
1894 | retval); | |
1895 | ||
1c03a2d0 | 1896 | if (notify) { |
8d65775d VK |
1897 | cpufreq_freq_transition_end(policy, &freqs, retval); |
1898 | ||
1c03a2d0 VK |
1899 | /* |
1900 | * Failed after setting to intermediate freq? Driver should have | |
1901 | * reverted back to initial frequency and so should we. Check | |
1902 | * here for intermediate_freq instead of get_intermediate, in | |
58405af6 | 1903 | * case we haven't switched to intermediate freq at all. |
1c03a2d0 VK |
1904 | */ |
1905 | if (unlikely(retval && intermediate_freq)) { | |
1906 | freqs.old = intermediate_freq; | |
1907 | freqs.new = policy->restore_freq; | |
1908 | cpufreq_freq_transition_begin(policy, &freqs); | |
1909 | cpufreq_freq_transition_end(policy, &freqs, 0); | |
1910 | } | |
1911 | } | |
1912 | ||
8d65775d VK |
1913 | return retval; |
1914 | } | |
1915 | ||
1da177e4 LT |
1916 | int __cpufreq_driver_target(struct cpufreq_policy *policy, |
1917 | unsigned int target_freq, | |
1918 | unsigned int relation) | |
1919 | { | |
7249924e | 1920 | unsigned int old_target_freq = target_freq; |
d218ed77 | 1921 | int index; |
c32b6b8e | 1922 | |
a7b422cd KRW |
1923 | if (cpufreq_disabled()) |
1924 | return -ENODEV; | |
1925 | ||
7249924e | 1926 | /* Make sure that target_freq is within supported range */ |
910c6e88 | 1927 | target_freq = clamp_val(target_freq, policy->min, policy->max); |
7249924e VK |
1928 | |
1929 | pr_debug("target for CPU %u: %u kHz, relation %u, requested %u kHz\n", | |
e837f9b5 | 1930 | policy->cpu, target_freq, relation, old_target_freq); |
5a1c0228 | 1931 | |
9c0ebcf7 VK |
1932 | /* |
1933 | * This might look like a redundant call as we are checking it again | |
1934 | * after finding index. But it is left intentionally for cases where | |
1935 | * exactly same freq is called again and so we can save on few function | |
1936 | * calls. | |
1937 | */ | |
5a1c0228 VK |
1938 | if (target_freq == policy->cur) |
1939 | return 0; | |
1940 | ||
1c03a2d0 VK |
1941 | /* Save last value to restore later on errors */ |
1942 | policy->restore_freq = policy->cur; | |
1943 | ||
1c3d85dd | 1944 | if (cpufreq_driver->target) |
6019d23a | 1945 | return cpufreq_driver->target(policy, target_freq, relation); |
9c0ebcf7 | 1946 | |
6019d23a RW |
1947 | if (!cpufreq_driver->target_index) |
1948 | return -EINVAL; | |
9c0ebcf7 | 1949 | |
d218ed77 | 1950 | index = cpufreq_frequency_table_target(policy, target_freq, relation); |
6019d23a | 1951 | |
23727845 | 1952 | return __target_index(policy, index); |
1da177e4 LT |
1953 | } |
1954 | EXPORT_SYMBOL_GPL(__cpufreq_driver_target); | |
1955 | ||
1da177e4 LT |
1956 | int cpufreq_driver_target(struct cpufreq_policy *policy, |
1957 | unsigned int target_freq, | |
1958 | unsigned int relation) | |
1959 | { | |
f1829e4a | 1960 | int ret = -EINVAL; |
1da177e4 | 1961 | |
ad7722da | 1962 | down_write(&policy->rwsem); |
1da177e4 LT |
1963 | |
1964 | ret = __cpufreq_driver_target(policy, target_freq, relation); | |
1965 | ||
ad7722da | 1966 | up_write(&policy->rwsem); |
1da177e4 | 1967 | |
1da177e4 LT |
1968 | return ret; |
1969 | } | |
1970 | EXPORT_SYMBOL_GPL(cpufreq_driver_target); | |
1971 | ||
de1df26b RW |
1972 | __weak struct cpufreq_governor *cpufreq_fallback_governor(void) |
1973 | { | |
1974 | return NULL; | |
1975 | } | |
1976 | ||
a92604b4 | 1977 | static int cpufreq_init_governor(struct cpufreq_policy *policy) |
1da177e4 | 1978 | { |
cc993cab | 1979 | int ret; |
6afde10c | 1980 | |
2f0aea93 VK |
1981 | /* Don't start any governor operations if we are entering suspend */ |
1982 | if (cpufreq_suspended) | |
1983 | return 0; | |
cb57720b EZ |
1984 | /* |
1985 | * Governor might not be initiated here if ACPI _PPC changed | |
1986 | * notification happened, so check it. | |
1987 | */ | |
1988 | if (!policy->governor) | |
1989 | return -EINVAL; | |
2f0aea93 | 1990 | |
1c256245 TR |
1991 | if (policy->governor->max_transition_latency && |
1992 | policy->cpuinfo.transition_latency > | |
1993 | policy->governor->max_transition_latency) { | |
de1df26b RW |
1994 | struct cpufreq_governor *gov = cpufreq_fallback_governor(); |
1995 | ||
1996 | if (gov) { | |
e837f9b5 JP |
1997 | pr_warn("%s governor failed, too long transition latency of HW, fallback to %s governor\n", |
1998 | policy->governor->name, gov->name); | |
6afde10c | 1999 | policy->governor = gov; |
de1df26b RW |
2000 | } else { |
2001 | return -EINVAL; | |
6afde10c | 2002 | } |
1c256245 | 2003 | } |
1da177e4 | 2004 | |
a92604b4 RW |
2005 | if (!try_module_get(policy->governor->owner)) |
2006 | return -EINVAL; | |
95731ebb | 2007 | |
a92604b4 | 2008 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); |
1da177e4 | 2009 | |
e788892b RW |
2010 | if (policy->governor->init) { |
2011 | ret = policy->governor->init(policy); | |
2012 | if (ret) { | |
36be3418 | 2013 | module_put(policy->governor->owner); |
e788892b RW |
2014 | return ret; |
2015 | } | |
36be3418 | 2016 | } |
1da177e4 | 2017 | |
a92604b4 RW |
2018 | return 0; |
2019 | } | |
2020 | ||
2021 | static void cpufreq_exit_governor(struct cpufreq_policy *policy) | |
2022 | { | |
2023 | if (cpufreq_suspended || !policy->governor) | |
2024 | return; | |
2025 | ||
2026 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2027 | ||
e788892b RW |
2028 | if (policy->governor->exit) |
2029 | policy->governor->exit(policy); | |
a92604b4 | 2030 | |
a92604b4 | 2031 | module_put(policy->governor->owner); |
1da177e4 LT |
2032 | } |
2033 | ||
0a300767 RW |
2034 | static int cpufreq_start_governor(struct cpufreq_policy *policy) |
2035 | { | |
2036 | int ret; | |
2037 | ||
a92604b4 RW |
2038 | if (cpufreq_suspended) |
2039 | return 0; | |
2040 | ||
2041 | if (!policy->governor) | |
2042 | return -EINVAL; | |
2043 | ||
2044 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2045 | ||
3bbf8fe3 RW |
2046 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) |
2047 | cpufreq_update_current_freq(policy); | |
2048 | ||
e788892b RW |
2049 | if (policy->governor->start) { |
2050 | ret = policy->governor->start(policy); | |
2051 | if (ret) | |
2052 | return ret; | |
2053 | } | |
2054 | ||
2055 | if (policy->governor->limits) | |
2056 | policy->governor->limits(policy); | |
d6ff44d6 | 2057 | |
d6ff44d6 | 2058 | return 0; |
0a300767 RW |
2059 | } |
2060 | ||
a92604b4 RW |
2061 | static void cpufreq_stop_governor(struct cpufreq_policy *policy) |
2062 | { | |
2063 | if (cpufreq_suspended || !policy->governor) | |
2064 | return; | |
2065 | ||
2066 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2067 | ||
e788892b RW |
2068 | if (policy->governor->stop) |
2069 | policy->governor->stop(policy); | |
a92604b4 RW |
2070 | } |
2071 | ||
2072 | static void cpufreq_governor_limits(struct cpufreq_policy *policy) | |
2073 | { | |
2074 | if (cpufreq_suspended || !policy->governor) | |
2075 | return; | |
2076 | ||
2077 | pr_debug("%s: for CPU %u\n", __func__, policy->cpu); | |
2078 | ||
e788892b RW |
2079 | if (policy->governor->limits) |
2080 | policy->governor->limits(policy); | |
0a300767 RW |
2081 | } |
2082 | ||
1da177e4 LT |
2083 | int cpufreq_register_governor(struct cpufreq_governor *governor) |
2084 | { | |
3bcb09a3 | 2085 | int err; |
1da177e4 LT |
2086 | |
2087 | if (!governor) | |
2088 | return -EINVAL; | |
2089 | ||
a7b422cd KRW |
2090 | if (cpufreq_disabled()) |
2091 | return -ENODEV; | |
2092 | ||
3fc54d37 | 2093 | mutex_lock(&cpufreq_governor_mutex); |
32ee8c3e | 2094 | |
3bcb09a3 | 2095 | err = -EBUSY; |
42f91fa1 | 2096 | if (!find_governor(governor->name)) { |
3bcb09a3 JF |
2097 | err = 0; |
2098 | list_add(&governor->governor_list, &cpufreq_governor_list); | |
1da177e4 | 2099 | } |
1da177e4 | 2100 | |
32ee8c3e | 2101 | mutex_unlock(&cpufreq_governor_mutex); |
3bcb09a3 | 2102 | return err; |
1da177e4 LT |
2103 | } |
2104 | EXPORT_SYMBOL_GPL(cpufreq_register_governor); | |
2105 | ||
1da177e4 LT |
2106 | void cpufreq_unregister_governor(struct cpufreq_governor *governor) |
2107 | { | |
4573237b VK |
2108 | struct cpufreq_policy *policy; |
2109 | unsigned long flags; | |
90e41bac | 2110 | |
1da177e4 LT |
2111 | if (!governor) |
2112 | return; | |
2113 | ||
a7b422cd KRW |
2114 | if (cpufreq_disabled()) |
2115 | return; | |
2116 | ||
4573237b VK |
2117 | /* clear last_governor for all inactive policies */ |
2118 | read_lock_irqsave(&cpufreq_driver_lock, flags); | |
2119 | for_each_inactive_policy(policy) { | |
18bf3a12 VK |
2120 | if (!strcmp(policy->last_governor, governor->name)) { |
2121 | policy->governor = NULL; | |
4573237b | 2122 | strcpy(policy->last_governor, "\0"); |
18bf3a12 | 2123 | } |
90e41bac | 2124 | } |
4573237b | 2125 | read_unlock_irqrestore(&cpufreq_driver_lock, flags); |
90e41bac | 2126 | |
3fc54d37 | 2127 | mutex_lock(&cpufreq_governor_mutex); |
1da177e4 | 2128 | list_del(&governor->governor_list); |
3fc54d37 | 2129 | mutex_unlock(&cpufreq_governor_mutex); |
1da177e4 LT |
2130 | return; |
2131 | } | |
2132 | EXPORT_SYMBOL_GPL(cpufreq_unregister_governor); | |
2133 | ||
2134 | ||
1da177e4 LT |
2135 | /********************************************************************* |
2136 | * POLICY INTERFACE * | |
2137 | *********************************************************************/ | |
2138 | ||
2139 | /** | |
2140 | * cpufreq_get_policy - get the current cpufreq_policy | |
29464f28 DJ |
2141 | * @policy: struct cpufreq_policy into which the current cpufreq_policy |
2142 | * is written | |
1da177e4 LT |
2143 | * |
2144 | * Reads the current cpufreq policy. | |
2145 | */ | |
2146 | int cpufreq_get_policy(struct cpufreq_policy *policy, unsigned int cpu) | |
2147 | { | |
2148 | struct cpufreq_policy *cpu_policy; | |
2149 | if (!policy) | |
2150 | return -EINVAL; | |
2151 | ||
2152 | cpu_policy = cpufreq_cpu_get(cpu); | |
2153 | if (!cpu_policy) | |
2154 | return -EINVAL; | |
2155 | ||
d5b73cd8 | 2156 | memcpy(policy, cpu_policy, sizeof(*policy)); |
1da177e4 LT |
2157 | |
2158 | cpufreq_cpu_put(cpu_policy); | |
1da177e4 LT |
2159 | return 0; |
2160 | } | |
2161 | EXPORT_SYMBOL(cpufreq_get_policy); | |
2162 | ||
153d7f3f | 2163 | /* |
037ce839 VK |
2164 | * policy : current policy. |
2165 | * new_policy: policy to be set. | |
153d7f3f | 2166 | */ |
037ce839 | 2167 | static int cpufreq_set_policy(struct cpufreq_policy *policy, |
3a3e9e06 | 2168 | struct cpufreq_policy *new_policy) |
1da177e4 | 2169 | { |
d9a789c7 RW |
2170 | struct cpufreq_governor *old_gov; |
2171 | int ret; | |
1da177e4 | 2172 | |
e837f9b5 JP |
2173 | pr_debug("setting new policy for CPU %u: %u - %u kHz\n", |
2174 | new_policy->cpu, new_policy->min, new_policy->max); | |
1da177e4 | 2175 | |
d5b73cd8 | 2176 | memcpy(&new_policy->cpuinfo, &policy->cpuinfo, sizeof(policy->cpuinfo)); |
1da177e4 | 2177 | |
fba9573b PX |
2178 | /* |
2179 | * This check works well when we store new min/max freq attributes, | |
2180 | * because new_policy is a copy of policy with one field updated. | |
2181 | */ | |
2182 | if (new_policy->min > new_policy->max) | |
d9a789c7 | 2183 | return -EINVAL; |
9c9a43ed | 2184 | |
1da177e4 | 2185 | /* verify the cpu speed can be set within this limit */ |
3a3e9e06 | 2186 | ret = cpufreq_driver->verify(new_policy); |
1da177e4 | 2187 | if (ret) |
d9a789c7 | 2188 | return ret; |
1da177e4 | 2189 | |
1da177e4 | 2190 | /* adjust if necessary - all reasons */ |
e041c683 | 2191 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2192 | CPUFREQ_ADJUST, new_policy); |
1da177e4 | 2193 | |
bb176f7d VK |
2194 | /* |
2195 | * verify the cpu speed can be set within this limit, which might be | |
2196 | * different to the first one | |
2197 | */ | |
3a3e9e06 | 2198 | ret = cpufreq_driver->verify(new_policy); |
e041c683 | 2199 | if (ret) |
d9a789c7 | 2200 | return ret; |
1da177e4 LT |
2201 | |
2202 | /* notification of the new policy */ | |
e041c683 | 2203 | blocking_notifier_call_chain(&cpufreq_policy_notifier_list, |
3a3e9e06 | 2204 | CPUFREQ_NOTIFY, new_policy); |
1da177e4 | 2205 | |
3a3e9e06 VK |
2206 | policy->min = new_policy->min; |
2207 | policy->max = new_policy->max; | |
1da177e4 | 2208 | |
e3c06236 SM |
2209 | policy->cached_target_freq = UINT_MAX; |
2210 | ||
2d06d8c4 | 2211 | pr_debug("new min and max freqs are %u - %u kHz\n", |
e837f9b5 | 2212 | policy->min, policy->max); |
1da177e4 | 2213 | |
1c3d85dd | 2214 | if (cpufreq_driver->setpolicy) { |
3a3e9e06 | 2215 | policy->policy = new_policy->policy; |
2d06d8c4 | 2216 | pr_debug("setting range\n"); |
d9a789c7 RW |
2217 | return cpufreq_driver->setpolicy(new_policy); |
2218 | } | |
1da177e4 | 2219 | |
0a300767 RW |
2220 | if (new_policy->governor == policy->governor) { |
2221 | pr_debug("cpufreq: governor limits update\n"); | |
a92604b4 | 2222 | cpufreq_governor_limits(policy); |
d6ff44d6 | 2223 | return 0; |
0a300767 | 2224 | } |
7bd353a9 | 2225 | |
d9a789c7 RW |
2226 | pr_debug("governor switch\n"); |
2227 | ||
2228 | /* save old, working values */ | |
2229 | old_gov = policy->governor; | |
2230 | /* end old governor */ | |
2231 | if (old_gov) { | |
45482c70 | 2232 | cpufreq_stop_governor(policy); |
36be3418 | 2233 | cpufreq_exit_governor(policy); |
1da177e4 LT |
2234 | } |
2235 | ||
d9a789c7 RW |
2236 | /* start new governor */ |
2237 | policy->governor = new_policy->governor; | |
a92604b4 | 2238 | ret = cpufreq_init_governor(policy); |
4bc384ae | 2239 | if (!ret) { |
0a300767 RW |
2240 | ret = cpufreq_start_governor(policy); |
2241 | if (!ret) { | |
2242 | pr_debug("cpufreq: governor change\n"); | |
2243 | return 0; | |
2244 | } | |
b7898fda | 2245 | cpufreq_exit_governor(policy); |
d9a789c7 RW |
2246 | } |
2247 | ||
2248 | /* new governor failed, so re-start old one */ | |
2249 | pr_debug("starting governor %s failed\n", policy->governor->name); | |
2250 | if (old_gov) { | |
2251 | policy->governor = old_gov; | |
a92604b4 | 2252 | if (cpufreq_init_governor(policy)) |
4bc384ae VK |
2253 | policy->governor = NULL; |
2254 | else | |
0a300767 | 2255 | cpufreq_start_governor(policy); |
d9a789c7 RW |
2256 | } |
2257 | ||
4bc384ae | 2258 | return ret; |
1da177e4 LT |
2259 | } |
2260 | ||
1da177e4 LT |
2261 | /** |
2262 | * cpufreq_update_policy - re-evaluate an existing cpufreq policy | |
2263 | * @cpu: CPU which shall be re-evaluated | |
2264 | * | |
25985edc | 2265 | * Useful for policy notifiers which have different necessities |
1da177e4 LT |
2266 | * at different times. |
2267 | */ | |
30248fef | 2268 | void cpufreq_update_policy(unsigned int cpu) |
1da177e4 | 2269 | { |
3a3e9e06 VK |
2270 | struct cpufreq_policy *policy = cpufreq_cpu_get(cpu); |
2271 | struct cpufreq_policy new_policy; | |
1da177e4 | 2272 | |
fefa8ff8 | 2273 | if (!policy) |
30248fef | 2274 | return; |
1da177e4 | 2275 | |
ad7722da | 2276 | down_write(&policy->rwsem); |
1da177e4 | 2277 | |
30248fef | 2278 | if (policy_is_inactive(policy)) |
182e36af | 2279 | goto unlock; |
182e36af | 2280 | |
2d06d8c4 | 2281 | pr_debug("updating policy for CPU %u\n", cpu); |
d5b73cd8 | 2282 | memcpy(&new_policy, policy, sizeof(*policy)); |
3a3e9e06 VK |
2283 | new_policy.min = policy->user_policy.min; |
2284 | new_policy.max = policy->user_policy.max; | |
1da177e4 | 2285 | |
bb176f7d VK |
2286 | /* |
2287 | * BIOS might change freq behind our back | |
2288 | * -> ask driver for current freq and notify governors about a change | |
2289 | */ | |
2ed99e39 | 2290 | if (cpufreq_driver->get && !cpufreq_driver->setpolicy) { |
30248fef | 2291 | if (cpufreq_suspended) |
742c87bf | 2292 | goto unlock; |
30248fef | 2293 | |
999f5729 | 2294 | new_policy.cur = cpufreq_update_current_freq(policy); |
30248fef | 2295 | if (WARN_ON(!new_policy.cur)) |
fefa8ff8 | 2296 | goto unlock; |
0961dd0d TR |
2297 | } |
2298 | ||
30248fef | 2299 | cpufreq_set_policy(policy, &new_policy); |
1da177e4 | 2300 | |
fefa8ff8 | 2301 | unlock: |
ad7722da | 2302 | up_write(&policy->rwsem); |
5a01f2e8 | 2303 | |
3a3e9e06 | 2304 | cpufreq_cpu_put(policy); |
1da177e4 LT |
2305 | } |
2306 | EXPORT_SYMBOL(cpufreq_update_policy); | |
2307 | ||
6f19efc0 LM |
2308 | /********************************************************************* |
2309 | * BOOST * | |
2310 | *********************************************************************/ | |
2311 | static int cpufreq_boost_set_sw(int state) | |
2312 | { | |
6f19efc0 LM |
2313 | struct cpufreq_policy *policy; |
2314 | int ret = -EINVAL; | |
2315 | ||
f963735a | 2316 | for_each_active_policy(policy) { |
f8bfc116 VK |
2317 | if (!policy->freq_table) |
2318 | continue; | |
49f18560 | 2319 | |
f8bfc116 VK |
2320 | ret = cpufreq_frequency_table_cpuinfo(policy, |
2321 | policy->freq_table); | |
2322 | if (ret) { | |
2323 | pr_err("%s: Policy frequency update failed\n", | |
2324 | __func__); | |
2325 | break; | |
6f19efc0 | 2326 | } |
f8bfc116 VK |
2327 | |
2328 | down_write(&policy->rwsem); | |
2329 | policy->user_policy.max = policy->max; | |
2330 | cpufreq_governor_limits(policy); | |
2331 | up_write(&policy->rwsem); | |
6f19efc0 LM |
2332 | } |
2333 | ||
2334 | return ret; | |
2335 | } | |
2336 | ||
2337 | int cpufreq_boost_trigger_state(int state) | |
2338 | { | |
2339 | unsigned long flags; | |
2340 | int ret = 0; | |
2341 | ||
2342 | if (cpufreq_driver->boost_enabled == state) | |
2343 | return 0; | |
2344 | ||
2345 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2346 | cpufreq_driver->boost_enabled = state; | |
2347 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2348 | ||
2349 | ret = cpufreq_driver->set_boost(state); | |
2350 | if (ret) { | |
2351 | write_lock_irqsave(&cpufreq_driver_lock, flags); | |
2352 | cpufreq_driver->boost_enabled = !state; | |
2353 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); | |
2354 | ||
e837f9b5 JP |
2355 | pr_err("%s: Cannot %s BOOST\n", |
2356 | __func__, state ? "enable" : "disable"); | |
6f19efc0 LM |
2357 | } |
2358 | ||
2359 | return ret; | |
2360 | } | |
2361 | ||
41669da0 | 2362 | static bool cpufreq_boost_supported(void) |
6f19efc0 | 2363 | { |
7a6c79f2 | 2364 | return likely(cpufreq_driver) && cpufreq_driver->set_boost; |
6f19efc0 | 2365 | } |
6f19efc0 | 2366 | |
44139ed4 VK |
2367 | static int create_boost_sysfs_file(void) |
2368 | { | |
2369 | int ret; | |
2370 | ||
c82bd444 | 2371 | ret = sysfs_create_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2372 | if (ret) |
2373 | pr_err("%s: cannot register global BOOST sysfs file\n", | |
2374 | __func__); | |
2375 | ||
2376 | return ret; | |
2377 | } | |
2378 | ||
2379 | static void remove_boost_sysfs_file(void) | |
2380 | { | |
2381 | if (cpufreq_boost_supported()) | |
c82bd444 | 2382 | sysfs_remove_file(cpufreq_global_kobject, &boost.attr); |
44139ed4 VK |
2383 | } |
2384 | ||
2385 | int cpufreq_enable_boost_support(void) | |
2386 | { | |
2387 | if (!cpufreq_driver) | |
2388 | return -EINVAL; | |
2389 | ||
2390 | if (cpufreq_boost_supported()) | |
2391 | return 0; | |
2392 | ||
7a6c79f2 | 2393 | cpufreq_driver->set_boost = cpufreq_boost_set_sw; |
44139ed4 VK |
2394 | |
2395 | /* This will get removed on driver unregister */ | |
2396 | return create_boost_sysfs_file(); | |
2397 | } | |
2398 | EXPORT_SYMBOL_GPL(cpufreq_enable_boost_support); | |
2399 | ||
6f19efc0 LM |
2400 | int cpufreq_boost_enabled(void) |
2401 | { | |
2402 | return cpufreq_driver->boost_enabled; | |
2403 | } | |
2404 | EXPORT_SYMBOL_GPL(cpufreq_boost_enabled); | |
2405 | ||
1da177e4 LT |
2406 | /********************************************************************* |
2407 | * REGISTER / UNREGISTER CPUFREQ DRIVER * | |
2408 | *********************************************************************/ | |
27622b06 | 2409 | static enum cpuhp_state hp_online; |
1da177e4 | 2410 | |
c4a3fa26 CY |
2411 | static int cpuhp_cpufreq_online(unsigned int cpu) |
2412 | { | |
2413 | cpufreq_online(cpu); | |
2414 | ||
2415 | return 0; | |
2416 | } | |
2417 | ||
2418 | static int cpuhp_cpufreq_offline(unsigned int cpu) | |
2419 | { | |
2420 | cpufreq_offline(cpu); | |
2421 | ||
2422 | return 0; | |
2423 | } | |
2424 | ||
1da177e4 LT |
2425 | /** |
2426 | * cpufreq_register_driver - register a CPU Frequency driver | |
2427 | * @driver_data: A struct cpufreq_driver containing the values# | |
2428 | * submitted by the CPU Frequency driver. | |
2429 | * | |
bb176f7d | 2430 | * Registers a CPU Frequency driver to this core code. This code |
63af4055 | 2431 | * returns zero on success, -EEXIST when another driver got here first |
32ee8c3e | 2432 | * (and isn't unregistered in the meantime). |
1da177e4 LT |
2433 | * |
2434 | */ | |
221dee28 | 2435 | int cpufreq_register_driver(struct cpufreq_driver *driver_data) |
1da177e4 LT |
2436 | { |
2437 | unsigned long flags; | |
2438 | int ret; | |
2439 | ||
a7b422cd KRW |
2440 | if (cpufreq_disabled()) |
2441 | return -ENODEV; | |
2442 | ||
1da177e4 | 2443 | if (!driver_data || !driver_data->verify || !driver_data->init || |
9c0ebcf7 | 2444 | !(driver_data->setpolicy || driver_data->target_index || |
9832235f RW |
2445 | driver_data->target) || |
2446 | (driver_data->setpolicy && (driver_data->target_index || | |
1c03a2d0 VK |
2447 | driver_data->target)) || |
2448 | (!!driver_data->get_intermediate != !!driver_data->target_intermediate)) | |
1da177e4 LT |
2449 | return -EINVAL; |
2450 | ||
2d06d8c4 | 2451 | pr_debug("trying to register driver %s\n", driver_data->name); |
1da177e4 | 2452 | |
fdd320da | 2453 | /* Protect against concurrent CPU online/offline. */ |
a92551e4 | 2454 | cpus_read_lock(); |
fdd320da | 2455 | |
0d1857a1 | 2456 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2457 | if (cpufreq_driver) { |
0d1857a1 | 2458 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
fdd320da RW |
2459 | ret = -EEXIST; |
2460 | goto out; | |
1da177e4 | 2461 | } |
1c3d85dd | 2462 | cpufreq_driver = driver_data; |
0d1857a1 | 2463 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
1da177e4 | 2464 | |
bc68b7df VK |
2465 | if (driver_data->setpolicy) |
2466 | driver_data->flags |= CPUFREQ_CONST_LOOPS; | |
2467 | ||
7a6c79f2 RW |
2468 | if (cpufreq_boost_supported()) { |
2469 | ret = create_boost_sysfs_file(); | |
2470 | if (ret) | |
2471 | goto err_null_driver; | |
2472 | } | |
6f19efc0 | 2473 | |
8a25a2fd | 2474 | ret = subsys_interface_register(&cpufreq_interface); |
8f5bc2ab | 2475 | if (ret) |
6f19efc0 | 2476 | goto err_boost_unreg; |
1da177e4 | 2477 | |
ce1bcfe9 VK |
2478 | if (!(cpufreq_driver->flags & CPUFREQ_STICKY) && |
2479 | list_empty(&cpufreq_policy_list)) { | |
1da177e4 | 2480 | /* if all ->init() calls failed, unregister */ |
6c770036 | 2481 | ret = -ENODEV; |
ce1bcfe9 VK |
2482 | pr_debug("%s: No CPU initialized for driver %s\n", __func__, |
2483 | driver_data->name); | |
2484 | goto err_if_unreg; | |
1da177e4 LT |
2485 | } |
2486 | ||
a92551e4 SAS |
2487 | ret = cpuhp_setup_state_nocalls_cpuslocked(CPUHP_AP_ONLINE_DYN, |
2488 | "cpufreq:online", | |
2489 | cpuhp_cpufreq_online, | |
2490 | cpuhp_cpufreq_offline); | |
27622b06 SAS |
2491 | if (ret < 0) |
2492 | goto err_if_unreg; | |
2493 | hp_online = ret; | |
5372e054 | 2494 | ret = 0; |
27622b06 | 2495 | |
2d06d8c4 | 2496 | pr_debug("driver %s up and running\n", driver_data->name); |
3834abb4 | 2497 | goto out; |
fdd320da | 2498 | |
8a25a2fd KS |
2499 | err_if_unreg: |
2500 | subsys_interface_unregister(&cpufreq_interface); | |
6f19efc0 | 2501 | err_boost_unreg: |
44139ed4 | 2502 | remove_boost_sysfs_file(); |
8f5bc2ab | 2503 | err_null_driver: |
0d1857a1 | 2504 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
1c3d85dd | 2505 | cpufreq_driver = NULL; |
0d1857a1 | 2506 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
3834abb4 | 2507 | out: |
a92551e4 | 2508 | cpus_read_unlock(); |
3834abb4 | 2509 | return ret; |
1da177e4 LT |
2510 | } |
2511 | EXPORT_SYMBOL_GPL(cpufreq_register_driver); | |
2512 | ||
1da177e4 LT |
2513 | /** |
2514 | * cpufreq_unregister_driver - unregister the current CPUFreq driver | |
2515 | * | |
bb176f7d | 2516 | * Unregister the current CPUFreq driver. Only call this if you have |
1da177e4 LT |
2517 | * the right to do so, i.e. if you have succeeded in initialising before! |
2518 | * Returns zero if successful, and -EINVAL if the cpufreq_driver is | |
2519 | * currently not initialised. | |
2520 | */ | |
221dee28 | 2521 | int cpufreq_unregister_driver(struct cpufreq_driver *driver) |
1da177e4 LT |
2522 | { |
2523 | unsigned long flags; | |
2524 | ||
1c3d85dd | 2525 | if (!cpufreq_driver || (driver != cpufreq_driver)) |
1da177e4 | 2526 | return -EINVAL; |
1da177e4 | 2527 | |
2d06d8c4 | 2528 | pr_debug("unregistering driver %s\n", driver->name); |
1da177e4 | 2529 | |
454d3a25 | 2530 | /* Protect against concurrent cpu hotplug */ |
a92551e4 | 2531 | cpus_read_lock(); |
8a25a2fd | 2532 | subsys_interface_unregister(&cpufreq_interface); |
44139ed4 | 2533 | remove_boost_sysfs_file(); |
a92551e4 | 2534 | cpuhp_remove_state_nocalls_cpuslocked(hp_online); |
1da177e4 | 2535 | |
0d1857a1 | 2536 | write_lock_irqsave(&cpufreq_driver_lock, flags); |
6eed9404 | 2537 | |
1c3d85dd | 2538 | cpufreq_driver = NULL; |
6eed9404 | 2539 | |
0d1857a1 | 2540 | write_unlock_irqrestore(&cpufreq_driver_lock, flags); |
a92551e4 | 2541 | cpus_read_unlock(); |
1da177e4 LT |
2542 | |
2543 | return 0; | |
2544 | } | |
2545 | EXPORT_SYMBOL_GPL(cpufreq_unregister_driver); | |
5a01f2e8 | 2546 | |
90de2a4a DA |
2547 | /* |
2548 | * Stop cpufreq at shutdown to make sure it isn't holding any locks | |
2549 | * or mutexes when secondary CPUs are halted. | |
2550 | */ | |
2551 | static struct syscore_ops cpufreq_syscore_ops = { | |
2552 | .shutdown = cpufreq_suspend, | |
2553 | }; | |
2554 | ||
c82bd444 VK |
2555 | struct kobject *cpufreq_global_kobject; |
2556 | EXPORT_SYMBOL(cpufreq_global_kobject); | |
2557 | ||
5a01f2e8 VP |
2558 | static int __init cpufreq_core_init(void) |
2559 | { | |
a7b422cd KRW |
2560 | if (cpufreq_disabled()) |
2561 | return -ENODEV; | |
2562 | ||
8eec1020 | 2563 | cpufreq_global_kobject = kobject_create_and_add("cpufreq", &cpu_subsys.dev_root->kobj); |
8aa84ad8 TR |
2564 | BUG_ON(!cpufreq_global_kobject); |
2565 | ||
90de2a4a DA |
2566 | register_syscore_ops(&cpufreq_syscore_ops); |
2567 | ||
5a01f2e8 VP |
2568 | return 0; |
2569 | } | |
d82f2692 | 2570 | module_param(off, int, 0444); |
5a01f2e8 | 2571 | core_initcall(cpufreq_core_init); |